Release 1.10 remediation: installers, IDE routing, local runtimes

[DougTrier]

Summary

This PR brings the current 1.10 remediation branch back into main, including the IDE/local-model fixes, security dependency cleanup, release packaging updates, and installer split work.

Changes

• Fixed IDE model routing so tool-capable agents and chat-only companions are handled more honestly.
• Improved local model readiness, beginner recommendations, and model/runtime diagnostics.
• Added release packaging support for separate Application and Supplemental installers.
• Fixed the Supplemental installer extraction bug where PowerShell could receive an empty payload path.
• Added .gitignore protection for local databases, .dev-app-data, SQLite sidecars, and key metadata.
• Backported the lopdf security fix through the vendored patched dependency.
• Updated 1.10 release metadata and documentation.
• Added/updated contract tests around IDE, model setup, release packaging, renderer boundaries, and local runtime behavior.

Testing

• node scripts\test_release_packaging_contract.cjs
• Supplemental installer rebuilt successfully
• Supplemental release asset replaced on GitHub release v1.10.0
• Verified updated Supplemental SHA-256: 6113E347A2FA074F9534BD9DC5610106933B471C6A9151F7FD70664794CB8A94
• Audited local database artifacts: no .db, key DB, or .dev-app-data files are tracked in Git history

Notes

The GitHub release asset was updated separately on release v1.10.0. This PR updates the source branch so main matches the current release work.