fix(desktop): harden sqlite bindings install flow

[Sun-sunshine06]

Summary

• make the desktop sqlite binding installer invoke prebuild-install in a Windows/pnpm-safe way
• allow the installer to skip missing Node prebuilds while still staging the Electron binding needed by the desktop app
• add a runtime fallback + regression test for binding path resolution

Testing

• corepack pnpm --filter @open-codesign/desktop test -- src/main/snapshots-db.binding.test.ts
• corepack pnpm --filter @open-codesign/desktop typecheck
• corepack pnpm exec biome check package.json apps/desktop/scripts/install-sqlite-bindings.cjs apps/desktop/src/main/snapshots-db.ts apps/desktop/src/main/snapshots-db.binding.test.ts

[github-actions]

Findings

• None.

Summary

• Review mode: initial
• No high-confidence issues were found in the added/modified lines of this diff.
• Residual risks/testing gaps: docs/VISION.md and docs/PRINCIPLES.md are not present in this checkout (Not found in repo/docs), and the new install flow is only unit-tested at binding-path resolution level (no integration test coverage in this PR for postinstall scenarios like missing Node prebuild).

Testing

• Not run (automation)

open-codesign Bot

[github-actions]

Findings

• None.

Summary

• Review mode: follow-up after new commits
• No high-confidence issues were found in the added/modified lines of this diff.
• Residual risks/testing gaps: install-flow changes in apps/desktop/scripts/install-sqlite-bindings.cjs are not covered by integration tests for postinstall permutations (for example missing Node prebuild while Electron prebuild is present); only binding-path unit tests were added in this PR. docs/VISION.md and docs/PRINCIPLES.md are Not found in repo/docs in this checkout.

Testing

• Not run (automation)

open-codesign Bot