Fix message model routing

[tiye]

Summary

• migrate persisted legacy messages that lack :thinking before strict Store decoding
• normalize current, historical, and archived message data through shared boundaries
• route Gemini menu variants to current API model IDs
• upgrade @google/genai to 2.23.0 and axios to 1.20.0
• upgrade alerts to 0.10.40 and respo-markdown to 0.4.40

Dependency fixes

• Fix indexed Markdown block mapping Respo/respo-markdown.calcit#50 fixes the generated acc() call in Markdown block mapping
• released respo-markdown 0.4.40 and alerts 0.10.40

Verification

• 7/7 Calcit regression tests pass, including legacy stored messages
• strict dependency resolution, check-only, dynamic-method, deprecated, dependency, and quality checks pass
• Node 24 production build and extension artifact checks pass
• generated Markdown utility now returns acc instead of calling acc()
• browser smoke test covers model switching, blank submit alert, and API-key prompt