refactor(backends): decompose adapter.ts into sidecarManager, progressLifecycle, secretOrchestrator

[aaight]

Summary

• Extract sidecar management into src/backends/sidecarManager.ts — moves createCompletionArtifacts(), hydrateReviewSidecar(), hydratePrSidecar(), hydrateNativeToolSidecars(), and cleanupTempFile()
• Extract progress lifecycle into src/backends/progressLifecycle.ts — moves buildProgressMonitorConfig() and isGitHubAckComment()
• Extract secret orchestration into src/backends/secretOrchestrator.ts — moves buildExecutionPlan(), resolvePartialExecutionPlan(), and adds injectRunLinkSecrets()
• Thin adapter.ts orchestrator — reduced from 623 lines to 183 lines, importing from the 3 new modules
• Unit tests added for each new module: sidecarManager.test.ts (24 tests), progressLifecycle.test.ts (19 tests), secretOrchestrator.test.ts (8 tests)

Closes: https://trello.com/c/JE1jx5i8/532-as-a-developer-i-want-backends-adapterts-decomposed-into-focused-modules-so-that-each-concern-is-independently-testable

Test plan

• All 55 existing adapter.test.ts tests pass
• 24 new sidecarManager.test.ts tests pass
• 19 new progressLifecycle.test.ts tests pass
• 8 new secretOrchestrator.test.ts tests pass
• Full test suite (6676 tests) passes with zero regressions
• npm run typecheck passes with no errors
• npm run lint passes with no errors

🤖 Generated with Claude Code

🕵️ claude-code · claude-sonnet-4-6 · run details

[codecov]

Codecov Report

❌ Patch coverage is 95.59229% with 16 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/backends/secretOrchestrator.ts	95.69%	8 Missing ⚠️
src/backends/sidecarManager.ts	94.44%	7 Missing ⚠️
src/backends/progressLifecycle.ts	97.77%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[nhopeatall]

Summary

LGTM — Clean decomposition of a 623-line orchestrator into three focused modules with clear responsibility boundaries, no circular dependencies, and comprehensive unit test coverage.

The refactoring is behavior-preserving: every extracted function is a verbatim move with only the necessary visibility changes (function → export function). The dependency graph flows cleanly: adapter.ts → {secretOrchestrator, progressLifecycle, sidecarManager}, and secretOrchestrator → {progressLifecycle, sidecarManager} with no cycles.

The one type change in hydrateNativeToolSidecars (from Awaited<ReturnType<AgentEngine['execute']>> to AgentEngineResult) is semantically identical since execute() returns Promise<AgentEngineResult>. The shared isGitHubAckComment utility is correctly placed in progressLifecycle.ts and imported by both consumers. The barrel export (index.ts) remains unchanged, so the public API surface is unaffected.

All 7 CI checks pass. 51 new tests cover the extracted modules well, including edge cases like ackCommentId: 0.

🕵️ claude-code · claude-opus-4-6 · run details