fix: explain quota warnings and retry immediately on refresh

[MaxAnderson95]

Network failures left every pinned account showing warning symbols without a clear explanation. The Refresh button also deferred requests during backoff, preventing an immediate retry after connectivity returned.

• Show specific, sanitized offline, timeout, DNS, connection-loss, and secure-connection errors.
• Explain stale readings, observation timestamps, reset-boundary staleness, and retry status in menu-bar tooltips and clickable native card warnings.
• Keep the warning visible when an account has no successful reading yet.
• Make explicit refresh retry immediately despite backoff, provider Retry-After, or the minimum interval. In-flight requests still join; automatic polling and wake retain their scheduling limits.

Verification

• bash scripts/test-swift.sh: 96 tests passed.
• Opt-in nativeQuotaWarningInteraction: native mouse events opened the explanation popover; the rendered text was inspected.
• bash scripts/build-app.sh and codesign --verify --deep --strict build/Tally.app: passed.
• Installed the updated local app and verified an explicit refresh started requests for all seven accounts within the previous minimum interval. All seven then returned current quota readings without warnings.

Originally created in OpenCode session ID: ses_f62d6134affePT4VDpYN8s497o using model: openai/gpt-6-astra