[ef-9] perf/fix: simplify codebase, fix bugs, optimize hot paths

[NiveditJain]

Summary

• 2 bug fixes: inverted error handling in resolveSubagentPath (non-ENOENT errors silently continued); negative durationMs from clock skew in log enrichment
• 5 performance fixes: regex literals hoisted to module-level constants (compiled once, not per-call); git rev-parse cached per-cwd in blockWorkOnMain (avoids repeated 3s synchronous block); policy registry lookup now uses a lazy index cache; Promise.all in project/session listing replaced with bounded batchAll(16) to prevent fd exhaustion; removed TTL refresh on cache hits in runtimeCache (was defeating the revalidateSeconds contract)
• 4 deduplication: extracted shared formatRelativeTime to lib/format-duration.ts; removed duplicate implementations in hooks-client.tsx and session-hooks-panel.tsx; replaced local CopyButton reimplementation with the shared component

Test plan

• bun run build — passes, no TypeScript errors
• bun run test:run — 709/709 tests pass
• Manual: launch dashboard, browse sessions, verify log viewer and copy buttons work
• Manual: trigger blockWorkOnMain twice on the same repo — second call should be instant (no execSync)

🤖 Generated with Claude Code

Summary by CodeRabbit

Release Notes

• Performance

  • Optimized internal caching and batch processing for improved responsiveness
  • Consolidated time formatting utilities for consistent display across the application
  • Enhanced policy evaluation with faster lookup caching

• Bug Fixes

  • Fixed potential negative duration values in activity logging
  • Improved error handling for file path resolution

[coderabbitai]

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Free

Run ID: 5d1de781-cb65-4e1b-9c44-29bfc86c4131

📥 Commits

Reviewing files that changed from the base of the PR and between 2b78c30 and 7034706.

📒 Files selected for processing (11)

• __tests__/hooks/builtin-policies.test.ts
• __tests__/lib/runtime-cache.test.ts
• app/components/session-hooks-panel.tsx
• app/policies/hooks-client.tsx
• lib/format-duration.ts
• lib/log-entries.ts
• lib/projects.ts
• lib/resolve-subagent-path.ts
• lib/runtime-cache.ts
• src/hooks/builtin-policies.ts
• src/hooks/policy-registry.ts

💤 Files with no reviewable changes (1)

• lib/runtime-cache.ts

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📝 Walkthrough

Walkthrough

The PR consolidates duplicate formatting utilities into shared modules, optimizes caching strategies across runtime and policy registries, hoists compiled regular expressions to module-level constants, introduces git branch caching, refactors async promise handling with concurrency limits, adjusts error handling logic, and updates tests to reflect new cache behaviors.

Changes

Cohort / File(s)	Summary
Formatting Consolidation lib/format-duration.ts, app/components/session-hooks-panel.tsx, app/policies/hooks-client.tsx	Extracted formatRelativeTime into shared utility; removed duplicate implementations and associated UI components (CopyButton), consolidating relative-time formatting across the codebase.
Runtime Cache & Policy Indexing lib/runtime-cache.ts, src/hooks/policy-registry.ts	Removed LRU-on-hit refresh behavior from runtime cache; added global index caching to policy registry to memoize filtered and sorted policy results by event type and tool name.
Performance Optimizations src/hooks/builtin-policies.ts	Hoisted module-level regex pattern constants for security checks (JWT, API keys, secrets, SQL, shell commands, git operations); introduced git branch caching per cwd with exported clearGitBranchCache() function for test isolation.
Test Updates __tests__/hooks/builtin-policies.test.ts, __tests__/lib/runtime-cache.test.ts	Added explicit cache invalidation calls in test afterEach hooks; adjusted LRU expectations to insertion-order eviction instead of recency-based reordering.
Error Handling & Async Management lib/resolve-subagent-path.ts, lib/projects.ts, lib/log-entries.ts	Changed error continuation logic to break on non-ENOENT errors; refactored unbounded Promise.all to batchAll with concurrency limit of 16; clamped tool-use result duration to non-negative values.

Sequence Diagram(s)

sequenceDiagram
    participant Caller as Policy Event Handler
    participant Registry as getPoliciesForEvent()
    participant Cache as Index Cache
    participant Store as Policy Registry Store

    Caller->>Registry: getPoliciesForEvent(eventType, toolName)
    Registry->>Cache: Check cache key (eventType, toolName)
    
    alt Cache Hit
        Cache-->>Registry: Return cached policies array
        Registry-->>Caller: Return policies
    else Cache Miss
        Registry->>Store: Query policies from registry
        Store-->>Registry: Return unfiltered policies
        Registry->>Registry: Filter by event type & tool name
        Registry->>Registry: Sort by priority
        Registry->>Cache: Store result in cache
        Cache-->>Registry: Cache updated
        Registry-->>Caller: Return policies
    end

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Estimated Code Review Effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Poem

A rabbit hops through caches deep,
With regex stored and branches to keep.
No more duplication, formatters now shared,
Concurrency bounded, performance prepared.
Hopping faster with each optimization! 🐰✨

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