[Obsidian review blockers] - Step 2: Clear strict source errors

[logancyang]

Relates to logancyang/obsidian-copilot-preview#285

Why

Obsidian's review reports error-level findings for broad any suppressions, undocumented lint disables, and a production module that crossed the gallery import fence. Those errors block approval even though they can be removed without changing runtime behavior.

What

This step clears only those error-level source findings:

• describes required lint suppressions and removes obsolete disables;
• replaces broad Orama and debounce type escapes with explicit TypeScript contracts; and
• moves gallery-only provider fixtures behind the existing allowed fixture boundary.

The resulting production JavaScript behavior is unchanged. The final diff is close to line-neutral and does not alter callbacks, logging, prompts, network requests, persistence, settings, or rendered UI.

Non goal

• Address warning-only async, network, desktop-runtime, DOM, settings-search, CSS, or dependency findings.
• Change search ranking, index contents, persistence formats, debounce timing, or error handling.
• Change provider transports, LLM prompts, or user-visible behavior.
• Add dependencies or CI workflows.

Screenshot

Not applicable — this PR changes source contracts, lint explanations, and development-only fixtures without changing rendered UI.

Risk

Medium

Criterion	Status	Reason
No behavior change, or a cosmetic/copy/docs/config change visible where it renders, or deterministic tests cover the changed behavior	✅	The source edits are comments, types, and development-only fixture placement
A defect would fail CI or be obvious on first use	✅	Type and import-boundary mistakes fail build or lint
A revert fully restores prior state, including persisted data	✅	No data migration or write path changes
No auth, permissions, secrets, or input-handling surface changes	✅	Those surfaces are untouched
No public API, plugin API, message, or on-disk contract changes	✅	The tightened types and fixtures are internal
No core-path concurrency, async-lifecycle, or state-machine changes	✅	Runtime control flow and scheduling are unchanged
No hot-path behavior lacks deterministic coverage	✅	No hot-path behavior changes; the full unit suite and build pass
No new dependency	✅	Dependency manifests are unchanged
Human-only behavior stays in one feature area and surfaces quickly	✅	There is no user-visible behavior change

Review: focus on the explicit Orama/debounce types, directive descriptions, and gallery fixture boundary; there should be no executable behavior change.

Verification

1. Run npm run format and npm run lint.
2. Run npm run build.
3. Run npm run test -- --runInBand.

[logancyang]

Conservative risk disposition

Risk: Medium — retained for error-level source findings only.

This PR was reduced to directive descriptions/removal of obsolete disables, explicit TypeScript contracts, and development-only gallery fixture placement. Callback forwarding, logging changes, provider behavior, prompts, persistence, and rendered UI were reverted. The final layer is near line-neutral and contains no runtime dependency change.

Recommendation: keep this as Step 2, reviewing for executable equivalence. Warning-only source cleanup remains deferred.