refactor: split large ResearchPage and AddActivityDialog

[BerryUIKI]

Summary

Split two large components (task #6).

Changes

• ResearchPage (695 lines): extracted ResearchProjectsSection / ResearchDocumentsSection / ResearchNotesSection into pages/research/components; the page keeps state, queries, mutations, and URL-context logic
• AddActivityDialog (528 lines): extracted a stateless presentational ActivityFormFields (values + change callbacks); the dialog keeps validation, submit logic, and focus trap

Base is feat/artifacts-delete (stacked PR); merge after #142.

[NoviUIKI]

Review summary — PR #143

Verdict: ✅ Approve

Well-executed decomposition. I verified the extraction is behavior-preserving: typecheck passes and the 38 tests covering this code all pass.

Critical

• None.

Important

• None.

Suggestions (non-blocking)

1. The researchOperationError banner is permanent once triggered (ResearchPage.tsx). It ORs five mutations' isError states, and React Query only resets isError for the mutation that is re-run — so after one failed delete, the banner stays on screen even after later operations succeed, and there's no dismiss. Consider tracking the last failed operation (or adding a dismiss) so the banner reflects current state.
2. ActivityFormFields takes ~20 value+callback props. Idiomatic controlled-component extraction, but if the form grows, a useReducer (or form library) in the container would cut the prop surface substantially.
3. Minor: the STATUSES label nested-ternary in ActivityFormFields.tsx is dense — a Record<ActivityStatus, MessageKey> lookup (mirroring ACTIVITY_TYPES) would read better.
4. Minor: the .mutate() error banner is generic (unexpectedError); a per-operation message ("Failed to delete project", etc.) would be more actionable.

Strengths

• Clean split: ResearchPage and AddActivityDialog keep all state, queries, mutations, and URL context; the new sections are presentational with value+callback props and fully typed interfaces (MessageKey, ReportType, ActivityType, …).
• Fixes a latent bug: the asset-select placeholder in AddActivityDialog previously rendered t("cancel") (i.e. "-- Cancel --"); it now uses the proper t("selectAsset") key.
• Surfaces previously-silent errors: the archive/complete/delete .mutate() calls (which swallow failures into isError) now render a role="alert" banner, matching the error-surfacing direction of PR #141.
• Removes the remaining (t(...) as any) casts (including the one in AddActivityDialog noted in the PR #140 review).
• New files get trailing newlines; git diff --check is clean.

Verification

• tsc --noEmit (apps/desktop): passes.
• ResearchPage.test.tsx (13), dialogs.test.tsx (20), ActivityList.test.tsx (5): 38/38 pass.
• git diff --check: clean.