- Restructure from patch collection to纲领性 document
- Add "第一性原理" section defining project essence
- Consolidate architecture decisions with clear mappings
- Streamline workflow and coding standards
- Remove troubleshooting details (defer to DEBUG_LESSONS.md)
- Reduce from 150 to 112 lines while increasing clarity

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Features:
- Add SessionBar component displaying aggregated session stats (cost, tokens, duration)
- Add BlockEditDialog for editing user inputs and creating branches
- Add type guards isStreamingStatus(), isErrorStatus() for BlockStatus checks
- Add isCompletedStatus() helper function

Code quality fixes (P0/P1/P2/P3):
- Fix JSX syntax errors: rename test files from .test.ts to .test.tsx
- Fix BlockStatus comparison bug (String() was always false)
- Reduce 'any' type usage in useBlockQueries.ts
- Extract magic number MILLI_CENTS_TO_USD constant
- Remove unused imports and variables

i18n:
- Add translations for session bar, edit dialog, and status labels

Refs #79

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

- Condense decision tree from verbose Chinese to concise English
- Simplify idea-researcher trigger flow
- Add language directive to CCRunner system prompt

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Backend changes:
- Add replaceUserInputs parameter to ForkBlock API for message editing
- Add reason validation and return InvalidArgument for empty reason
- Store fork metadata (forked_from, fork_reason, fork_type) for debugging
- Remove duplicate log entry from ForkBlock (keep service layer only)
- Add unit tests: TestForkBlock_WithReplaceUserInputs, TestForkBlock_EmptyReason

Frontend changes:
- Simplify BlockEditDialog UI: remove "original message" display area
- Merge multiple user inputs (with newlines) for editing
- Fix handleEdit to pass complete MessageBlock for input merging
- Remove onSend call after ForkBlock (was creating duplicate block)
- Add new i18n keys: message, edit_placeholder

Bug fix:
- Fix mouse cursor flickering on /auth/signup page caused by overly
  broad [tabIndex] CSS selector targeting Radix UI components

Refs #79

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

… audit fixes (Issue #79)

This commit completes the P0-P3 phase tasks and addresses all code audit findings:

**P2 Tasks:**
- Add BlockSummary restoration from persisted Block.sessionStats after page refresh
- Implement friendly branch path numbering (0/1/2 → A.2.3) with Base26 conversion
- Integrate SessionBar into ChatHeader for PC, mobile-only standalone display

**P3 Tasks:**
- Update AI_CHAT_INTERFACE.md to v0.93.1 with new UI patterns

**Code Audit Fixes:**
- P1-#1: Add safeBigIntToNumber with MAX_SAFE_INTEGER boundary check
- P2-#1: Add MAX_ITERATIONS limit to toBase26 to prevent potential infinite loops
- P2-#2: Optimize calculateSessionStats to process only last 100 blocks
- P3-#1: Replace hardcoded Chinese text with i18n t() calls
- P3-#2: Add detailed comment for MILLI_CENTS_TO_USD constant

**New Components:**
- HeaderSessionStats: Mode-differentiated session stats (Normal/Geek/Evolution)

**Bug Fixes:**
- Fix ForkBlock protobuf serialization using create(UserInputSchema, ...)
- Fix ToolCalls duplication with occurrence-based deduplication
- Fix import ordering per Biome lint rules

Refs #79

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

The sync.RWMutex field was declared but never used since the underlying
LRUCache handles its own locking internally.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

- Remove unused BlockListCacheData interface (re-added for internal use)
- Fix protobuf mock creation using proper types
- Change \`as any\` to \`as unknown as Type\` for observer mocks
- Use EmptySchema for delete/append operations
- Use ListBlocksResponseSchema for list operations
- Import EmptySchema from @bufbuild/protobuf/wkt

Refs #79

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

- Update @testing-library/jest-dom from 6.6.0 to 6.9.1
- Update @testing-library/react from 16.2.0 to 16.3.2