docs(architecture): add large file analysis for refactoring

Analyze 9 TypeScript files over 700 LOC for refactoring opportunities:

High priority:
- memory/manager.ts (2178 LOC) - Split by responsibility

Medium priority:
- bash-tools.exec.ts (1495 LOC) - Extract validation/sanitization
- tts/tts.ts (1473 LOC) - Split by provider
- exec-approvals.ts (1267 LOC) - Extract approval strategies
- node-host/runner.ts (1199 LOC) - Extract message handlers
- media-understanding/runner.ts (1118 LOC) - Extract provider adapters

Leave as-is:
- line/flex-templates.ts - Static templates
- cli/update-cli.ts - Sequential workflow
- config/schema.ts - Declarative schemas

Part of Phase 2: Architecture Cleanup

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

docs/architecture/large-file-analysis.md

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+# Large File Analysis for Refactoring
+
+This document analyzes TypeScript files over 700 LOC for potential refactoring opportunities.
+
+## Summary
+
+| File | LOC | Priority | Recommendation |
+|------|-----|----------|----------------|
+| memory/manager.ts | 2178 | High | Split by responsibility |
+| line/flex-templates.ts | 1507 | Low | Template data, leave as-is |
+| agents/bash-tools.exec.ts | 1495 | Medium | Extract validation/sanitization |
+| tts/tts.ts | 1473 | Medium | Split by provider |
+| infra/exec-approvals.ts | 1267 | Medium | Extract approval strategies |
+| cli/update-cli.ts | 1204 | Low | Sequential workflow, ok as-is |
+| node-host/runner.ts | 1199 | Medium | Extract message handlers |
+| media-understanding/runner.ts | 1118 | Medium | Extract provider adapters |
+| config/schema.ts | 987 | Low | Zod schema, ok as-is |
+
+## Detailed Analysis
+
+### memory/manager.ts (2178 LOC) - HIGH PRIORITY
+
+**Current Structure:**
+- Single `MemoryIndexManager` class handling everything
+- Responsibilities: embedding generation, vector storage, FTS indexing, file watching, search
+
+**Refactoring Opportunities:**
+1. Extract `MemoryEmbeddingService` - embedding generation, batching, caching
+2. Extract `MemoryFileWatcher` - chokidar setup, debouncing, dirty tracking
+3. Extract `MemoryIndexer` - chunking, indexing, schema management
+4. Keep `MemorySearchManager` for search orchestration
+
+**Benefits:**
+- Each module testable in isolation
+- Clearer separation of async/sync concerns
+- Easier to add new embedding providers
+
+### agents/bash-tools.exec.ts (1495 LOC) - MEDIUM PRIORITY
+
+**Current Structure:**
+- One large `createExecTool` factory function
+- Handles: command parsing, sandboxing, approval, execution, output formatting
+
+**Refactoring Opportunities:**
+1. Extract `CommandSanitizer` - input validation, escaping
+2. Extract `SandboxResolver` - sandbox mode detection, policy application
+3. Keep execution logic as core
+
+**Considerations:**
+- Highly cohesive as a tool definition
+- Breaking apart may reduce readability of the tool's behavior
+
+### tts/tts.ts (1473 LOC) - MEDIUM PRIORITY
+
+**Current Structure:**
+- Many exported utility functions
+- Provider-specific logic mixed together (OpenAI, ElevenLabs, Edge)
+
+**Refactoring Opportunities:**
+1. Extract `tts-openai.ts` - OpenAI-specific synthesis
+2. Extract `tts-elevenlabs.ts` - ElevenLabs-specific synthesis
+3. Extract `tts-edge.ts` - Edge TTS synthesis
+4. Keep `tts.ts` as coordinator with prefs management
+
+**Benefits:**
+- Provider implementations isolated
+- Easier to add new TTS providers
+- Core prefs/config logic cleaner
+
+### infra/exec-approvals.ts (1267 LOC) - MEDIUM PRIORITY
+
+**Current Structure:**
+- Approval system for dangerous commands
+- Multiple approval strategies and state management
+
+**Refactoring Opportunities:**
+1. Extract approval strategy implementations
+2. Extract approval state persistence
+3. Keep approval orchestration in main file
+
+### node-host/runner.ts (1199 LOC) - MEDIUM PRIORITY
+
+**Current Structure:**
+- Node process runner for agent execution
+- Message handling, state management, IPC
+
+**Refactoring Opportunities:**
+1. Extract message type handlers
+2. Extract state machine logic
+3. Keep runner lifecycle in main file
+
+### media-understanding/runner.ts (1118 LOC) - MEDIUM PRIORITY
+
+**Current Structure:**
+- Media analysis orchestration
+- Multiple provider adapters
+
+**Refactoring Opportunities:**
+1. Extract provider-specific adapters
+2. Extract result normalization
+3. Keep orchestration in main file
+
+## Files to Leave As-Is
+
+### line/flex-templates.ts (1507 LOC)
+Large but contains static template definitions for LINE Flex messages. No logic to split.
+
+### cli/update-cli.ts (1204 LOC)
+Sequential update workflow. Splitting would reduce readability without improving maintainability.
+
+### config/schema.ts (987 LOC)
+Zod schema definitions. Schemas are declarative and benefit from co-location.
+
+## Recommended Refactoring Order
+
+1. **memory/manager.ts** - Highest ROI, complex responsibilities
+2. **tts/tts.ts** - Clear provider boundaries
+3. **exec-approvals.ts** - Growing complexity with approval strategies
+4. **bash-tools.exec.ts** - If validation complexity increases
+5. **node-host/runner.ts** - If message handling expands
+
+## Completed Refactoring
+
+- **session-utils.ts** (644 LOC) - Split into avatar, agents, store modules ✓