Refine self-improvement review guidance

[Wenjie Fan (gggdttt)]

Summary

Refine the second self-improvement batch into evidence-backed BCQuality guidance rather than copying reaction-generated changes verbatim.

• narrow IsHandled reset findings to values that can actually carry true, including loop-carried state
• retire local Label scope as a correctness/localization rule
• allow semantic capture/reset/assert UI-handler tests and reserve queues for interaction contracts
• require restart-safe persisted checkpoints without weakening bounded retrieval
• align ModifyAll/DeleteAll fallback guidance with documented platform conditions

False-positive boundaries

• A fresh local Boolean is already false for one non-looping raise. A local declared outside a loop initializes once and can carry true across iterations. A later raise reached only after a semantically valid if IsHandled then exit; remains proven false.
• Independent event seams use independent handled state so one handled event does not suppress a downstream publisher.
• Procedure-local Labels are supported and included in the extension translation pipeline; object scope is only a possible maintainability convention.
• [HandlerFunctions] proves listed handlers execute. Missing semantic verification is minor; queue storage is not mandatory for every handler. Fixtures cover omitted handlers, listed-but-unreached handlers, and meaningful capture/assert verification.
• Persisted retry progress and bounded next-N retrieval are separate requirements. A full-tail FindSet remains unbounded, and the checkpoint sample initializes its persisted watermark on cold start.
• Progress UX permits an explicit row loop only when the equivalent bulk API already falls back to individual operations and semantics are preserved. DeleteAll guidance includes trigger code, related subscribers, security filtering, Media/MediaSet, and companion-field fallback conditions.

Validation

• python .github/scripts/validate_frontmatter.py --root .
• tools/Test-ReviewFixtures.ps1 -Root . -PrepareDirectory <temp>
• .github/scripts/Test-KnowledgeIndex.ps1 -Root .
• git diff --check

Deliberately unchanged

• internal-access-is-not-a-security-boundary
• ErrorInfo boundary guidance
• the PR #7938 unreachable-case candidate
• no swallowed-handler-assertion warning
• existing article slugs and paths