fix(dashboard): fix review trigger toggles showing under PM section

[aaight]

Summary

• Bug fix: getTriggersForAgent() now accepts an optional opts parameter with category filter, preventing SCM-only triggers (Own PRs Only, External PRs, On Review Requested) from bleeding into the "Project Management Triggers" UI section for the Review agent
• Secondary bug fix: handleSaveScm in AgentSection now uses extractRelevantTriggers() for proper dot-notation key nesting (e.g., reviewTrigger.ownPrsOnly) instead of flat key lookup that would corrupt saved data
• Unit tests: New test file tests/unit/web/triggerAgentMapping.test.ts covering category filtering and backward compatibility

Changes

• web/src/lib/trigger-agent-mapping.ts: Updated getTriggersForAgent signature from (agentType, pmProvider?) to (agentType, opts?) with optional category and pmProvider fields
• web/src/components/projects/project-agent-configs.tsx: Updated PM trigger query to pass { pmProvider, category: 'pm' }, SCM trigger query to pass { category: 'scm' }, and handleSaveScm to use extractRelevantTriggers()
• tests/unit/web/triggerAgentMapping.test.ts: New test file with 9 tests

Test plan

• getTriggersForAgent('review', { category: 'pm' }) returns empty array
• getTriggersForAgent('review', { category: 'scm' }) returns 3 review triggers
• getTriggersForAgent('briefing', { category: 'pm', pmProvider: 'trello' }) returns PM-only triggers
• getTriggersForAgent('briefing', { category: 'scm' }) returns empty array
• Backward compatibility: getTriggersForAgent('review') without opts still returns all triggers
• All 9 unit tests pass
• Lint clean, typecheck passes

Card: https://trello.com/c/RLtfQJeE/88-fix-review-trigger-toggles-showing-under-pm-section-in-dashboard

🤖 Generated with Claude Code

[nhopeatall]

🔍 Reviewing PR...

[nhopeatall]

LGTM — Clean, well-scoped bug fix with good test coverage.

Bug 1 (PM section bleed): The old getTriggersForAgent('review', pmProvider) only filtered by pmProvider, so review SCM triggers (which have no pmProvider) passed through unconditionally and appeared in the "Project Management Triggers" UI. Adding category filtering to the function and passing { category: 'pm' } / { category: 'scm' } from the call sites cleanly resolves this.

Bug 2 (flat key save corruption): handleSaveScm previously used relevant[t.key] = ... which would save dot-notation keys like reviewTrigger.ownPrsOnly as flat string keys rather than the expected nested { reviewTrigger: { ownPrsOnly: ... } } structure. Switching to the existing extractRelevantTriggers() helper (already used by handleSavePm) fixes the data shape.

Backward compatibility: When opts is omitted, both new filter conditions short-circuit (optional chaining on undefined), so unparameterized calls return all triggers as before. The test suite verifies this explicitly.

All 9 unit tests are well-structured and CI is green.