refactor(agents): move contextPipeline from strategies to triggers

[zbigniewsobiecki]

Summary

• Moves context pipeline configuration from strategies.contextPipeline to trigger-specific definitions
• Provides more explicit control over what context each trigger fetches
• Fixes copy-paste error in respond-to-review.yaml taskPrompt
• Adds missing trailingMessage to respond-to-pr-comment.yaml for consistency

Changes

Schema & Logic

• Remove contextPipeline from StrategiesSchema (now trigger-only)
• Simplify resolveContextPipeline() to return [] when no trigger matches
• Add comprehensive JSDoc documenting edge cases

Agent Definitions

• All YAML files now have contextPipeline per-trigger instead of in strategies
• Fix respond-to-review.yaml taskPrompt (was incorrectly copy-pasted from respond-to-pr-comment)
• Add trailingMessage to respond-to-pr-comment.yaml

API & UI

• Remove contextStepNames from schema endpoint (frontend no longer needs it)
• Simplify strategies section in dashboard editor

Tests

• Update schema and loader tests for new structure
• Add 4 edge case tests for resolveContextPipeline:
  • triggerType: undefined → []
  • Unknown triggerType → []
  • Agent with no triggers → []
  • Empty string triggerType → []

Benefits

1. Explicit context per trigger: Each trigger clearly defines what context it needs
2. No hidden defaults: Removed fallback behavior that could mask misconfiguration
3. Simpler mental model: One place to look for context configuration

Test plan

• npm run typecheck passes
• npm run lint passes
• npm test passes (3726 tests)
• Pre-commit hooks pass (lint, typecheck)
• Pre-push hooks pass (test)

🤖 Generated with Claude Code