fix: Activity timeline for company and deal entities

[Rishavraaj]

fix: Activity timeline for company and deal entities

Problem

Company and deal activity timelines were returning 404 errors:

• Company 404 — the frontend API client pluralized "company" as "companys" instead of "companies", so requests hit a non-existent route.
• Deal 404 — DealActivitiesController was never implemented, so GET /deals/:id/activities and POST /deals/:id/activities/comments didn't exist.

Contact activities were unaffected as "contact" → "contacts" is a regular plural.

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Changes

Backend

• Add DealActivitiesController with GET /deals/:dealId/activities and POST /deals/:dealId/activities/comments routes
• Register DealActivitiesController in SalesModule

Frontend

• Fix entity pluralization in activities.ts: company → companies (was companys)

E2E Tests

• Expand DealDetailPage with full activity helper methods (createComment, editComment, cancelEditComment, isPostButtonDisabled, hasNoActivityMessage, etc.)
• Uncomment and re-enable 3 previously skipped deal activity tests in deals.spec.ts
• Add deal-activities.spec.ts with a full timeline test suite

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Test Plan

• Navigate to a company detail page — activity timeline loads without 404
• Post a comment on a company — comment appears in timeline
• Navigate to a deal detail page — activity timeline loads without 404
• Post a comment on a deal — comment appears in timeline
• Edit and cancel editing a deal comment
• Run bun e2e — all deal activity tests pass

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Root Cause

Entity	Plural (expected)	Plural (actual)	Result
contact	contacts	contacts	✅
company	companies	companys	❌ 404
deal	deals	deals	❌ 404 (no controller)