refactor(router): extract platformClients.ts to eliminate credential resolution duplication

[aaight]

Summary

Refactors the src/router/ platform-dispatch files to eliminate ~20× duplicated credential resolution scaffolding across acknowledgments.ts, reactions.ts, and notifications.ts.

• Extracted src/router/platformClients.ts: Centralized credential resolution helpers for Trello (getTrelloCredentialsForProject), JIRA (getJiraAuthForProject), and GitHub (getGitHubTokenForProject). Also moved bot identity caches (resolveTrelloBotMemberId, resolveJiraBotAccountId) and the JIRA cloudId cache (getJiraCloudId) to this shared module.
• Simplified acknowledgments.ts: Replaced 6× duplicated let x; try { x = await getIntegrationCredential(...) blocks with 2-line platform client calls (~333→197 lines).
• Simplified reactions.ts: Replaced credential scaffolding in 3 platform senders with platform client calls (~283→229 lines).
• Simplified notifications.ts: Replaced credential scaffolding in Trello and JIRA timeout notifiers with platform client calls (~221→205 lines).
• Created tests/unit/router/platformClients.test.ts: 30 new tests covering credential resolution, caching, TTL expiry, and error handling for all platform client helpers.
• Backward compatibility: Bot identity helpers and cache reset functions are re-exported from acknowledgments.ts so existing callers are unaffected.

Test plan

• All 221 router tests pass (including 30 new platformClients.test.ts tests)
• TypeScript typecheck passes with zero errors
• Biome lint passes with zero errors
• Pre-existing test failures in config/projects.test.ts confirmed to be pre-existing (not introduced by this PR)

Card

https://trello.com/c/7lj1Vu6W/80-find-top-candidate-for-refactoring-and-plan-clean-refactoring-of-it-look-for-god-classes-modules-functions-files-and-code-duplic

🤖 Generated with Claude Code

[zbigniewsobiecki]

@aaight resolve conflicts and explain how did they happen

[aaight]

Request Addressed

What was asked

Resolve merge conflicts with the dev branch and explain how they happened.

Changes Made

• Merged dev into refactor/platform-clients, resolving conflicts in all 5 files
• Adopted dev's naming convention from PR refactor(router): extract shared credential resolution & platform API helpers #492 (resolveTrelloCredentials, resolveJiraCredentials, resolveGitHubHeaders, JiraCredentials.auth)
• Preserved this PR's unique additions (bot identity caches, JIRA cloudId cache, GitHub token resolution) in platformClients.ts
• Updated all callers and tests to use consistent naming
• Combined both PRs' test suites (now 33 tests in platformClients.test.ts)

Root Cause

PR #492 (refactor/router-platform-clients) was merged to dev while this PR was open. Both PRs independently extracted credential resolution into platformClients.ts but with different naming conventions and scope.

Verification

• All 229 router tests passing
• TypeScript typecheck passing (zero errors)
• Biome lint passing (zero errors)
• Pre-existing config/projects.test.ts failures confirmed unrelated

[aaight]

Conflicts resolved and pushed! ✅

What caused the conflicts:

PR #492 () was merged to dev while this PR was open. Both PRs independently extracted credential resolution into platformClients.ts, but with different naming conventions and different scope:

Aspect	PR #492 (merged to dev)	This PR #494
Trello helper	resolveTrelloCredentials	getTrelloCredentialsForProject
JIRA helper	resolveJiraCredentials	getJiraAuthForProject
JIRA auth field	auth	basicAuth
JIRA type	JiraCredentials	JiraAuth
GitHub headers	resolveGitHubHeaders() helper	inline headers
Bot caches	stayed in acknowledgments.ts	moved to platformClients.ts
JIRA cloudId cache	stayed in reactions.ts	moved to platformClients.ts
GitHub token resolver	stayed in acknowledgments.ts	moved to platformClients.ts

Resolution strategy: Adopted dev's naming/interface for the overlapping credential resolution helpers (since PR #492 was already merged and has consumers), then layered on this PR's unique contributions (bot identity caches, JIRA cloudId cache, GitHub token resolution in platformClients.ts).

All 5 conflicted files resolved: platformClients.ts, acknowledgments.ts, reactions.ts, notifications.ts, and platformClients.test.ts. All 229 router tests pass. Typecheck and lint clean.