diff --git a/.jules/palette.md b/.jules/palette.md
index c05638899..91300fb20 100644
--- a/.jules/palette.md
+++ b/.jules/palette.md
@@ -1,3 +1,7 @@
-## 2024-05-19 - Replace HTML disabled with aria-disabled="true" for Accessible Tooltips
-**Learning:** Native HTML `disabled` attributes completely hide elements from screen readers and block all pointer/hover events, preventing tooltips from functioning for disabled elements.
-**Action:** Replace `disabled` with `aria-disabled="true"`, enforce block click handlers via `e.preventDefault()`, and add a title tooltip directly to the element to maintain full tooltip accessibility and keyboard focus support for visually impaired and mouse users.
+## 2026-09-09 - Accessible Tooltips on Disabled Elements
+**Learning:** `aria-disabled="true"` exposes unavailable state but does not suppress activation. Icon-only controls therefore need an accessible name independent of the tooltip, and unavailable activation must still be blocked in code.
+**Action:** Keep unavailable icon buttons focusable with `aria-disabled="true"`, give the trigger an `aria-label` matching the Tooltip text, and route pointer or keyboard-generated clicks through `preventUnavailableAction`. Use the design-system Tooltip only to explain the unavailable state; do not log or expose user-controlled values through tooltip copy.
+
+## 2026-09-11 - Preserve doctoring security boundaries during regeneration
+**Learning:** This Tooltip slice cites external MDN, W3C, and Base UI documentation. Two later branch regenerations removed the reviewed `Security Notes` paragraph even though the runtime trust/network boundary had not changed, repeatedly reopening the same governance finding.
+**Action:** When updating `docs/doctoring/sidebar-disabled-tooltips.md`, preserve its `Security Notes` section whenever external references remain. The note must keep those URLs documentation-only and state that this Tooltip slice adds no runtime fetch/navigation, subprocess, IPC, updater, model-download, credential, or trust-boundary path. If that security boundary truly changes, update the note and tests/review evidence explicitly rather than deleting it as formatting or generated-copy cleanup.
diff --git a/apps/desktop/src/App.test.tsx b/apps/desktop/src/App.test.tsx
index 3eed386f8..58d217e7e 100644
--- a/apps/desktop/src/App.test.tsx
+++ b/apps/desktop/src/App.test.tsx
@@ -225,7 +225,7 @@ describe("App", () => {
     for (const name of ["Import", "Export"]) {
       const navButton = within(primaryNav).getByRole("button", { name });
       expect(navButton).toHaveAttribute("aria-disabled", "true");
-      expect(navButton).toHaveAttribute("title", "Coming soon");
+      expect(navButton).not.toHaveAttribute("title");
       expect(navButton).not.toBeDisabled();
     }
     fireEvent.click(within(primaryNav).getByRole("button", { name: "Import" }));
@@ -236,7 +236,7 @@ describe("App", () => {
     for (const name of ["Import", "Export"]) {
       const navButton = within(compactNav).getByRole("button", { name: `${name} compact view` });
       expect(navButton).toHaveAttribute("aria-disabled", "true");
-      expect(navButton).toHaveAttribute("title", "Coming soon");
+      expect(navButton).not.toHaveAttribute("title");
       expect(navButton).not.toBeDisabled();
     }
     fireEvent.click(within(compactNav).getByRole("button", { name: "Import compact view" }));
diff --git a/apps/desktop/src/App.tsx b/apps/desktop/src/App.tsx
index f3d678454..42b28cb9e 100644
--- a/apps/desktop/src/App.tsx
+++ b/apps/desktop/src/App.tsx
@@ -24,6 +24,7 @@ import {
   X,
   type LucideIcon,
 } from "lucide-react";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
 import {
   SUPPORTED_AUDIO_FORMATS,
   type AnalysisJobRequest,
@@ -565,25 +566,43 @@ export function App() {
               const { label, enabled, active, title } = navButtonState(item);
               const { icon: Icon, view } = item;
 
-              return (
+              const buttonClass = `flex min-h-11 w-full items-center gap-3 rounded-xl px-3 text-left text-sm font-semibold transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 ${
+                active
+                  ? "bg-blue-600/70 text-white shadow-[0_12px_30px_rgba(37,99,235,0.32)]"
+                  : enabled
+                    ? "text-slate-200 hover:bg-white/5"
+                    : "cursor-not-allowed text-slate-500 opacity-70"
+              }`;
+
+              const buttonContent = (
+                <>
+                  <Icon className="size-5" aria-hidden="true" />
+                  {label}
+                </>
+              );
+
+              return enabled ? (
                 <button
                   key={item.labelKey}
                   type="button"
                   aria-current={active ? "page" : undefined}
-                  aria-disabled={enabled ? undefined : true}
-                  title={title}
-                  onClick={enabled && view ? () => handleNavSelect(view) : blockInactiveNavActivation}
-                  className={`flex min-h-11 w-full items-center gap-3 rounded-xl px-3 text-left text-sm font-semibold transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 ${
-                    active
-                      ? "bg-blue-600/70 text-white shadow-[0_12px_30px_rgba(37,99,235,0.32)]"
-                      : enabled
-                        ? "text-slate-200 hover:bg-white/5"
-                        : "cursor-not-allowed text-slate-500 opacity-70"
-                  }`}
+                  onClick={view ? () => handleNavSelect(view) : blockInactiveNavActivation}
+                  className={buttonClass}
                 >
-                  <Icon className="size-5" aria-hidden="true" />
-                  {label}
+                  {buttonContent}
                 </button>
+              ) : (
+                <Tooltip key={item.labelKey}>
+                  <TooltipTrigger
+                    type="button"
+                    aria-disabled="true"
+                    onClick={blockInactiveNavActivation}
+                    className={buttonClass}
+                  >
+                    {buttonContent}
+                  </TooltipTrigger>
+                  {title && <TooltipContent>{title}</TooltipContent>}
+                </Tooltip>
               );
             })}
           </nav>
@@ -611,26 +630,30 @@ export function App() {
             </div>
 
             <div className="flex items-center justify-between text-slate-400">
-              <button
-                type="button"
-                aria-disabled={true}
-                aria-label={t("settingsComingSoon")}
-                title={t("settingsComingSoon")}
-                onClick={preventUnavailableAction}
-                className="inline-flex cursor-not-allowed items-center justify-center rounded-xl p-2 text-slate-600 transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
-              >
-                <Settings className="size-5" aria-hidden="true" />
-              </button>
-              <button
-                type="button"
-                aria-disabled={true}
-                aria-label={t("helpComingSoon")}
-                title={t("helpComingSoon")}
-                onClick={preventUnavailableAction}
-                className="inline-flex cursor-not-allowed items-center justify-center rounded-xl p-2 text-slate-600 transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
-              >
-                <CircleHelp className="size-5" aria-hidden="true" />
-              </button>
+              <Tooltip>
+                <TooltipTrigger
+                  type="button"
+                  aria-disabled="true"
+                  aria-label={t("settingsComingSoon")}
+                  onClick={preventUnavailableAction}
+                  className="inline-flex cursor-not-allowed items-center justify-center rounded-xl p-2 text-slate-600 transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
+                >
+                  <Settings className="size-5" aria-hidden="true" />
+                </TooltipTrigger>
+                <TooltipContent>{t("settingsComingSoon")}</TooltipContent>
+              </Tooltip>
+              <Tooltip>
+                <TooltipTrigger
+                  type="button"
+                  aria-disabled="true"
+                  aria-label={t("helpComingSoon")}
+                  onClick={preventUnavailableAction}
+                  className="inline-flex cursor-not-allowed items-center justify-center rounded-xl p-2 text-slate-600 transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
+                >
+                  <CircleHelp className="size-5" aria-hidden="true" />
+                </TooltipTrigger>
+                <TooltipContent>{t("helpComingSoon")}</TooltipContent>
+              </Tooltip>
             </div>
           </div>
         </aside>
@@ -641,26 +664,45 @@ export function App() {
               const { label, enabled, active, title } = navButtonState(item);
               const { icon: Icon, view } = item;
 
-              return (
+              const buttonClass = `inline-flex min-h-10 shrink-0 items-center gap-2 rounded-xl px-3 text-sm font-semibold transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 ${
+                active
+                  ? "bg-blue-600/70 text-white"
+                  : enabled
+                    ? "text-slate-200 hover:bg-white/5"
+                    : "cursor-not-allowed text-slate-500 opacity-70"
+              }`;
+
+              const buttonContent = (
+                <>
+                  <Icon className="size-4" aria-hidden="true" />
+                  {label}
+                </>
+              );
+
+              return enabled ? (
                 <button
                   key={item.labelKey}
                   type="button"
                   aria-current={active ? "page" : undefined}
                   aria-label={`${label} ${t("compactViewSuffix")}`}
-                  aria-disabled={enabled ? undefined : true}
-                  title={title}
-                  onClick={enabled && view ? () => handleNavSelect(view) : blockInactiveNavActivation}
-                  className={`inline-flex min-h-10 shrink-0 items-center gap-2 rounded-xl px-3 text-sm font-semibold transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300 ${
-                    active
-                      ? "bg-blue-600/70 text-white"
-                      : enabled
-                        ? "text-slate-200 hover:bg-white/5"
-                        : "cursor-not-allowed text-slate-500 opacity-70"
-                  }`}
+                  onClick={view ? () => handleNavSelect(view) : blockInactiveNavActivation}
+                  className={buttonClass}
                 >
-                  <Icon className="size-4" aria-hidden="true" />
-                  {label}
+                  {buttonContent}
                 </button>
+              ) : (
+                <Tooltip key={item.labelKey}>
+                  <TooltipTrigger
+                    type="button"
+                    aria-label={`${label} ${t("compactViewSuffix")}`}
+                    aria-disabled="true"
+                    onClick={blockInactiveNavActivation}
+                    className={buttonClass}
+                  >
+                    {buttonContent}
+                  </TooltipTrigger>
+                  {title && <TooltipContent>{title}</TooltipContent>}
+                </Tooltip>
               );
             })}
           </nav>
@@ -709,15 +751,17 @@ export function App() {
                         aria-describedby={selectionError && selectionErrorSource === "youtube" ? "selection-error" : undefined}
                       />
                       {youtubeUrl && !analysisInFlight && !isStarting && !isImporting ? (
-                        <button
-                          type="button"
-                          onClick={handleClearYoutubeUrl}
-                          className="absolute right-1 top-1/2 inline-flex size-8 -translate-y-1/2 items-center justify-center rounded-md text-slate-400 transition hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
-                          aria-label={t("clearYoutubeUrl")}
-                          title={t("clearYoutubeUrl")}
-                        >
-                          <X className="size-4" aria-hidden="true" />
-                        </button>
+                        <Tooltip>
+                          <TooltipTrigger
+                            type="button"
+                            onClick={handleClearYoutubeUrl}
+                            className="absolute right-1 top-1/2 inline-flex size-8 -translate-y-1/2 items-center justify-center rounded-md text-slate-400 transition hover:bg-white/10 hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-cyan-300"
+                            aria-label={t("clearYoutubeUrl")}
+                          >
+                            <X className="size-4" aria-hidden="true" />
+                          </TooltipTrigger>
+                          <TooltipContent>{t("clearYoutubeUrl")}</TooltipContent>
+                        </Tooltip>
                       ) : null}
                     </div>
                   </div>
@@ -756,17 +800,29 @@ export function App() {
                     {t("saveProject")}
                   </Button>
                 ) : (
-                  <Button
-                    aria-disabled="true"
-                    title={t("saveRequiresAnalysis")}
-                    onClick={preventUnavailableAction}
-                    variant="outline"
-                    className="min-h-11 border-white/10 bg-white/5 font-semibold text-slate-100"
-                    aria-label={t("saveProject")}
-                  >
-                    <Save className="mr-2 size-4" aria-hidden="true" />
-                    {t("saveProject")}
-                  </Button>
+                  <>
+                    <Tooltip>
+                      <TooltipTrigger
+                        render={
+                          <Button
+                            aria-disabled="true"
+                            aria-describedby="save-project-unavailable-reason"
+                            onClick={preventUnavailableAction}
+                            variant="outline"
+                            className="min-h-11 border-white/10 bg-white/5 font-semibold text-slate-100"
+                            aria-label={t("saveProject")}
+                          />
+                        }
+                      >
+                        <Save className="mr-2 size-4" aria-hidden="true" />
+                        {t("saveProject")}
+                      </TooltipTrigger>
+                      <TooltipContent>{t("saveRequiresAnalysis")}</TooltipContent>
+                    </Tooltip>
+                    <span id="save-project-unavailable-reason" className="sr-only">
+                      {t("saveRequiresAnalysis")}
+                    </span>
+                  </>
                 )}
                 <Button
                   onClick={handleStartAnalysis}
diff --git a/apps/desktop/src/App.unavailableSave.test.tsx b/apps/desktop/src/App.unavailableSave.test.tsx
new file mode 100644
index 000000000..60de27ea7
--- /dev/null
+++ b/apps/desktop/src/App.unavailableSave.test.tsx
@@ -0,0 +1,58 @@
+import { fireEvent, render, screen } from "@testing-library/react";
+import { expect, it, vi } from "vitest";
+import { App } from "./App";
+
+vi.mock("./features/score/pdfjs", () => ({
+  configureScorePdfWorker: vi.fn(),
+  loadScorePdf: vi.fn(() => ({
+    promise: Promise.resolve({ numPages: 1, getPage: vi.fn() }),
+    destroy: vi.fn(() => Promise.resolve())
+  }))
+}));
+
+it("keeps unavailable Save focusable without native-title-only help", () => {
+  const languageSpy = vi.spyOn(window.navigator, "language", "get").mockReturnValue("en-US");
+
+  try {
+    render(<App />);
+
+    const saveButton = screen.getByRole("button", { name: /save project/i });
+    expect(saveButton).toHaveAttribute("aria-disabled", "true");
+    expect(saveButton).not.toHaveAttribute("disabled");
+    expect(saveButton).not.toHaveAttribute("title");
+
+    const descriptionId = saveButton.getAttribute("aria-describedby");
+    expect(descriptionId).toBeTruthy();
+    expect(document.getElementById(descriptionId!)).toHaveTextContent(
+      "Analyze a song to enable saving"
+    );
+
+    fireEvent.click(saveButton);
+    expect(saveButton).toHaveAttribute("aria-disabled", "true");
+  } finally {
+    languageSpy.mockRestore();
+  }
+});
+
+it("keeps App icon tooltip triggers free of native title fallbacks", () => {
+  const languageSpy = vi.spyOn(window.navigator, "language", "get").mockReturnValue("en-US");
+
+  try {
+    render(<App />);
+
+    const settingsButton = screen.getByRole("button", { name: /settings coming soon/i });
+    const helpButton = screen.getByRole("button", { name: /help coming soon/i });
+    expect(settingsButton).not.toHaveAttribute("title");
+    expect(helpButton).not.toHaveAttribute("title");
+
+    const youtubeInput = screen.getByRole("textbox", { name: /youtube url/i });
+    fireEvent.change(youtubeInput, {
+      target: { value: "https://youtube.com/watch?v=abc123DEF45" }
+    });
+
+    const clearButton = screen.getByRole("button", { name: /clear youtube url/i });
+    expect(clearButton).not.toHaveAttribute("title");
+  } finally {
+    languageSpy.mockRestore();
+  }
+});
diff --git a/apps/desktop/src/components/ui/tooltip.resilience.test.tsx b/apps/desktop/src/components/ui/tooltip.resilience.test.tsx
new file mode 100644
index 000000000..df187580e
--- /dev/null
+++ b/apps/desktop/src/components/ui/tooltip.resilience.test.tsx
@@ -0,0 +1,51 @@
+import { fireEvent, render, screen } from "@testing-library/react"
+import { describe, expect, it, vi } from "vitest"
+
+import { Tooltip, TooltipContent, TooltipTrigger } from "./tooltip"
+
+describe("Tooltip resilience contract", () => {
+  it("keeps Base UI trigger button semantics and native props", () => {
+    const onClick = vi.fn()
+
+    render(
+      <Tooltip>
+        <TooltipTrigger
+          type="button"
+          aria-disabled="true"
+          aria-label="Settings coming soon"
+          className="focus-contract"
+          onClick={onClick}
+        >
+          Settings
+        </TooltipTrigger>
+        <TooltipContent>Settings coming soon</TooltipContent>
+      </Tooltip>
+    )
+
+    const trigger = screen.getByRole("button", { name: "Settings coming soon" })
+    expect(trigger.tagName).toBe("BUTTON")
+    expect(trigger).toHaveAttribute("type", "button")
+    expect(trigger).toHaveAttribute("aria-disabled", "true")
+    expect(trigger).toHaveClass("focus-contract")
+
+    fireEvent.click(trigger)
+    expect(onClick).toHaveBeenCalledTimes(1)
+  })
+
+  it("bounds expanded locale copy and disables decorative motion when requested", () => {
+    render(
+      <Tooltip open>
+        <TooltipTrigger aria-label="Settings coming soon">Settings</TooltipTrigger>
+        <TooltipContent>
+          Einstellungen sind in dieser Version noch nicht verfügbar und werden später bereitgestellt.
+        </TooltipContent>
+      </Tooltip>
+    )
+
+    const tooltipContent = document.querySelector('[data-slot="tooltip-content"]')
+    expect(tooltipContent).toBeTruthy()
+    expect(tooltipContent).toHaveClass("max-w-[min(20rem,calc(100vw-2rem))]")
+    expect(tooltipContent).toHaveClass("break-words")
+    expect(tooltipContent).toHaveClass("motion-reduce:transition-none")
+  })
+})
diff --git a/apps/desktop/src/components/ui/tooltip.tsx b/apps/desktop/src/components/ui/tooltip.tsx
index 8b954764b..790da93b1 100644
--- a/apps/desktop/src/components/ui/tooltip.tsx
+++ b/apps/desktop/src/components/ui/tooltip.tsx
@@ -36,8 +36,8 @@ function TooltipContent({
         <TooltipPrimitive.Popup
           data-slot="tooltip-content"
           className={cn(
-            "bg-primary text-primary-foreground w-fit rounded-md px-3 py-1.5 text-xs text-balance",
-            "data-[starting-style]:opacity-0 data-[ending-style]:opacity-0 transition-opacity",
+            "bg-primary text-primary-foreground w-fit max-w-[min(20rem,calc(100vw-2rem))] break-words rounded-md px-3 py-1.5 text-xs text-balance",
+            "data-[starting-style]:opacity-0 data-[ending-style]:opacity-0 transition-opacity motion-reduce:transition-none",
             className
           )}
           {...props}
diff --git a/docs/doctoring/sidebar-disabled-tooltips.md b/docs/doctoring/sidebar-disabled-tooltips.md
new file mode 100644
index 000000000..c93b77bdb
--- /dev/null
+++ b/docs/doctoring/sidebar-disabled-tooltips.md
@@ -0,0 +1,78 @@
+# App unavailable-tooltip accessibility boundary
+
+## Problem and buyer impact
+
+Several App controls are intentionally unavailable while prerequisite product state is missing. Settings and Help remain discoverable in the sidebar, Import and Export are unavailable navigation entries, and Save is unavailable until a rehearsal song exists. Native `title` text is not the product authority for any of these states: controls need an accessible action name independent of tooltip rendering, activation must remain suppressed while `aria-disabled="true"` keeps them in the focus order, and the reason for an unavailable buyer action must remain available to assistive technology without depending on hover.
+
+The shared Tooltip primitive also used an opacity transition for appearance/disappearance without an explicit reduced-motion override. The effect is decorative rather than necessary to convey state, so the primitive respects the operating-system/browser reduced-motion preference.
+
+## Constraints
+
+- Keep unavailable features unavailable; this slice does not implement Settings, Help, Import, Export, or a pre-analysis Save path.
+- Keep intentionally discoverable controls keyboard-focusable and expose a localized action name independently of Tooltip popup state.
+- `aria-disabled` is semantic state, not an interaction lock. `preventUnavailableAction` / `blockInactiveNavActivation` remain responsible for suppressing pointer- and keyboard-generated activation.
+- For Save, preserve `Save Project` as the action name and expose `Analyze a song to enable saving` as a persistent description as well as the visual Tooltip explanation. Do not collapse the reason into the action name.
+- Do not create a second locale ledger or copy translation authority into the Tooltip primitive.
+- Long translated text must wrap within the viewport instead of depending on a fixed English-sized popup.
+- The primitive and jsdom tests must not claim browser, Narrator, VoiceOver, touch, or visual acceptance.
+
+## Decision
+
+The sidebar and unavailable navigation entries use the existing design-system `Tooltip`, with `TooltipTrigger` retaining `aria-disabled="true"`, a localized `aria-label`, and an explicit activation guard. The shared popup keeps a viewport-bounded maximum width, word breaking for long tokens, and `motion-reduce:transition-none` for its decorative opacity transition.
+
+The unavailable Save control uses the same Tooltip system but preserves the existing styled `Button` through Base UI's `TooltipTrigger render={...}` composition. The rendered button remains focusable with `aria-disabled="true"`, has no native `title`, and references an always-present screen-reader-only explanation through `aria-describedby`. The Tooltip repeats that localized reason visually for pointer/focus discovery. The successful Save path is unchanged.
+
+A focused Save regression first locked the missing contract: focusable `aria-disabled`, no native `title`, and a persistent localized description. The production repair then composed Tooltip + Button without changing Save activation authority. Existing Tooltip resilience tests continue to verify Base UI native-button/prop forwarding and responsive/reduced-motion class contracts.
+
+This remains a component/source contract rather than product-level accessibility acceptance.
+
+Alternatives rejected:
+
+- Native `disabled`: removes these intentionally discoverable controls from ordinary keyboard focus.
+- `aria-disabled` without an event guard: exposes state but leaves activation behavior enabled.
+- Native `title`: hover-dependent, inconsistent with the shared product Tooltip, and not a sufficient persistent explanation for the unavailable Save state.
+- Tooltip-only explanation: makes the Save reason depend on popup state; the persistent `aria-describedby` alternative remains available when the popup is absent.
+- Replacing `Save Project` with the prerequisite reason as the accessible name: loses the action identity instead of describing why that action is unavailable.
+- Radix `asChild` repair: BandScope uses Base UI Tooltip. Base UI supports composing a trigger with another rendered component via `render`.
+- Fixed popup width sized for English/Korean: does not address CJK/European-language expansion or narrow viewports.
+- Removing all Tooltip animation globally: unnecessary; honoring the user preference is the narrower control.
+
+## Evidence and claim boundary
+
+WAI-ARIA 1.3 distinguishes an accessible name from a more verbose accessible description and recommends `aria-describedby` when a short description already exists in the DOM. W3C Authoring Practices likewise documents a button referencing sibling descriptive text with `aria-describedby` and notes that `title` is a lower-priority fallback that can be inaccessible to users without a hover-capable pointing device. That directly supports keeping `Save Project` as the action name while exposing the prerequisite reason as a separate persistent description.
+
+MDN states that `aria-disabled="true"` communicates disabled semantics but does not suppress functionality; developers must suppress behavior themselves. W3C WCAG 2.2 SC 1.4.10 explains that ordinary text content should reflow within a viewport rather than force two-dimensional scrolling. MDN defines `prefers-reduced-motion` as the user preference for reducing non-essential motion. These sources support the interaction, description, wrapping, and motion-preference boundaries; they do not prove BandScope conformance by themselves.
+
+The repository lockfile on this stack identifies `@base-ui/react` 1.7.0. The Base UI trigger contract renders a button by default and supports the `render` composition used for the unavailable Save Button. Earlier review that reasoned from Radix-specific semantics was dismissed only after the repository added Base UI trigger-forwarding evidence; that dismissal is not an approval and does not satisfy current-head review.
+
+Current automated evidence covers App DOM semantics, the focused unavailable-Save description contract, Base UI trigger forwarding, and the Tooltip class contract. Current-head browser geometry, actual hover/focus/Escape popup behavior, forced-colors, Narrator/VoiceOver announcements, pointer/touch behavior, 400% zoom, and KO/EN/JA/ZH/VI/ES/DE/FR rendered acceptance remain separate UI Delivery Gate evidence.
+
+## TRACEABILITY
+
+- App product integration: `apps/desktop/src/App.tsx`
+- Focused unavailable-Save regression: `apps/desktop/src/App.unavailableSave.test.tsx`
+- Existing App integration regressions: `apps/desktop/src/App.test.tsx`
+- Shared primitive: `apps/desktop/src/components/ui/tooltip.tsx`
+- Trigger-forwarding and expanded-copy/reduced-motion regression: `apps/desktop/src/components/ui/tooltip.resilience.test.tsx`
+- Reviewer learning note: `.jules/palette.md`
+- Dependency authority: root `package-lock.json`, `@base-ui/react` 1.7.0 on this stack
+- Upstream implementation authority: Base UI Tooltip/Button render composition
+- Accessibility description authority: WAI-ARIA 1.3 and W3C Authoring Practices accessible-name/description guidance
+
+## Security Notes
+
+### Trust boundary
+
+The MDN, W3C, and upstream Base UI URLs in this doctoring note are documentation references only. BandScope does not fetch, execute, embed, or navigate to them at runtime, and this Tooltip change adds no network request, WebView navigation, subprocess, IPC, updater, model-download, credential, or trust-boundary path. Runtime behavior remains limited to the existing local design-system Tooltip, Button, and localized in-process strings.
+
+## References
+
+Mozilla Developer Network. (2025, November 6). *ARIA: aria-disabled attribute*. MDN Web Docs. https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Reference/Attributes/aria-disabled
+
+Mozilla Developer Network. (2026, June 10). *prefers-reduced-motion CSS media feature*. MDN Web Docs. https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules/@media/prefers-reduced-motion
+
+World Wide Web Consortium. (2026, June 4). *Accessible Rich Internet Applications (WAI-ARIA) 1.3*. https://www.w3.org/TR/2026/WD-wai-aria-1.3-20260604/
+
+World Wide Web Consortium, Web Accessibility Initiative. (n.d.). *Providing accessible names and descriptions*. Retrieved September 21, 2026, from https://www.w3.org/WAI/ARIA/apg/practices/names-and-descriptions/
+
+W3C Accessibility Guidelines Working Group. (2026, August 10). *Understanding Success Criterion 1.4.10: Reflow*. W3C Web Accessibility Initiative. https://www.w3.org/WAI/WCAG22/Understanding/reflow