Add resume and history system for makima (#1)

This PR implements a comprehensive resume and history system that enables:

1. **History Viewing**
   - View complete conversation history for contracts across all phases
   - View conversation history for individual tasks
   - View task output/tool call history with timestamps
   - View checkpoint history
   - Timeline view showing all activities

2. **Resume System**
   - Resume interrupted supervisor conversations with full context
   - Resume interrupted task conversations
   - Resume from specific checkpoints
   - Continue tasks from previous task state (worktree inheritance)

3. **Rewind/Restore Features**
   - Rewind code to any checkpoint (git restore)
   - Rewind conversation to any point
   - Create new branches from historical points
   - Fork tasks from any point in history

- New migration: 20250117000000_history_tables.sql
  - conversation_snapshots table for storing conversation state
  - history_events table for unified timeline
  - Added forking fields to tasks table
  - Added conversation_snapshot_id to task_checkpoints

- ConversationSnapshot, HistoryEvent, ConversationMessage
- Request/response types for resume and rewind operations
- Query filter types for history endpoints

- CRUD functions for conversation_snapshots
- CRUD functions for history_events
- Task conversation retrieval from task_events

- GET /api/v1/contracts/{id}/history
- GET /api/v1/contracts/{id}/supervisor/conversation
- GET /api/v1/mesh/tasks/{id}/conversation
- GET /api/v1/timeline
- POST /api/v1/contracts/{id}/supervisor/resume
- POST /api/v1/mesh/tasks/{id}/rewind
- POST /api/v1/mesh/tasks/{id}/fork
- POST /api/v1/mesh/tasks/{id}/checkpoints/{cid}/resume
- POST /api/v1/mesh/tasks/{id}/checkpoints/{cid}/branch
- POST /api/v1/contracts/{id}/supervisor/conversation/rewind

- task-history: View task conversation history
- task-checkpoints: List task checkpoints
- resume: Resume supervisor after interruption
- task-resume-from: Resume task from checkpoint
- task-rewind: Rewind task code to checkpoint
- task-fork: Fork task from historical point
- rewind-conversation: Rewind supervisor conversation

1 files changed, 240 insertions, 0 deletions

diff --git a/makima/docs/USER-STORIES-resume-history-system.md b/makima/docs/USER-STORIES-resume-history-system.md
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+# Resume and History System - User Stories
+
+## Epic: History Viewing
+
+### US-HV-01: View Contract History Timeline
+**As a** developer using Makima
+**I want to** view a complete timeline of all activities in my contract
+**So that** I can understand what happened across all phases and tasks
+
+**Acceptance Criteria:**
+- Timeline shows all activities chronologically
+- Activities include task creation, completions, checkpoints, phase changes, and chat messages
+- Timeline can be filtered by phase
+- Timeline can be filtered by time range
+- Timeline supports pagination for large datasets
+
+### US-HV-02: View Task Conversation History
+**As a** developer
+**I want to** view the complete conversation history for any task
+**So that** I can understand what the AI did and how it arrived at its solution
+
+**Acceptance Criteria:**
+- All messages are displayed in chronological order
+- Tool calls are shown with their inputs
+- Tool results are shown with outputs
+- Error messages are clearly highlighted
+- Token usage and cost are displayed if available
+
+### US-HV-03: View Checkpoint with Diff
+**As a** developer
+**I want to** see what code changes were made in each checkpoint
+**So that** I can review the work done at each step
+
+**Acceptance Criteria:**
+- Checkpoint details show commit message and timestamp
+- Diff shows files changed with additions/deletions
+- Diff uses syntax highlighting for code
+- Can navigate between checkpoints
+- Shows summary statistics (files changed, lines added/removed)
+
+### US-HV-04: View Supervisor Conversation
+**As a** developer managing a contract
+**I want to** view the supervisor's conversation history
+**So that** I can understand how tasks were orchestrated and decisions were made
+
+**Acceptance Criteria:**
+- Full conversation history is displayed
+- Spawned tasks are linked and visible
+- Pending tasks are indicated
+- Phase information is shown
+- Tool calls and decisions are visible
+
+## Epic: Resume System
+
+### US-RS-01: Resume Interrupted Supervisor
+**As a** developer
+**I want to** resume my supervisor conversation after a daemon disconnect
+**So that** I don't lose my progress and context
+
+**Acceptance Criteria:**
+- Supervisor can be resumed with full conversation context
+- Can choose resume mode (continue, restart phase, from checkpoint)
+- Resume works on any available daemon
+- Original context is preserved
+- New activity continues from where it left off
+
+### US-RS-02: Resume Interrupted Task
+**As a** developer
+**I want to** resume a task that was interrupted
+**So that** the AI can continue without redoing completed work
+
+**Acceptance Criteria:**
+- Task resumes with conversation context
+- Worktree state is preserved
+- Can specify context size limit
+- Resume works on different daemon if needed
+- Progress is not lost
+
+### US-RS-03: Resume from Specific Checkpoint
+**As a** developer
+**I want to** resume work from a specific checkpoint
+**So that** I can try a different approach from a known good state
+
+**Acceptance Criteria:**
+- Can select any checkpoint to resume from
+- Code state matches checkpoint
+- Can optionally include conversation up to that point
+- New task is created with appropriate context
+- Original task remains unchanged
+
+### US-RS-04: Continue from Previous Task
+**As a** developer
+**I want to** start a new task that inherits another task's worktree
+**So that** I can build on previous work without copying files manually
+
+**Acceptance Criteria:**
+- New task inherits worktree state from source task
+- Can specify which files to copy
+- Git history is preserved
+- Source task is not modified
+- New task gets its own isolated worktree
+
+## Epic: Rewind/Restore Features
+
+### US-RW-01: Rewind Code to Checkpoint
+**As a** developer
+**I want to** rewind my code to a previous checkpoint
+**So that** I can undo changes and try a different approach
+
+**Acceptance Criteria:**
+- Can select any checkpoint to rewind to
+- Can choose to discard current changes
+- Can choose to preserve current state as branch
+- Can choose to stash current changes
+- Rewind is atomic (all or nothing)
+
+### US-RW-02: Rewind Conversation
+**As a** developer
+**I want to** rewind the conversation to an earlier point
+**So that** I can remove problematic AI responses and try again
+
+**Acceptance Criteria:**
+- Can specify rewind point by message ID, timestamp, or message count
+- Messages after rewind point are removed
+- Optionally rewind code to matching checkpoint
+- Supervisor state is updated
+- Can continue conversation from new point
+
+### US-RW-03: Fork Task from History
+**As a** developer
+**I want to** create a new task from a point in history
+**So that** I can explore an alternative approach without losing original work
+
+**Acceptance Criteria:**
+- Can fork from any checkpoint
+- Can fork from any conversation point
+- New task gets code state from fork point
+- Can optionally include conversation history
+- Original task is not modified
+- New branch is created in git
+
+### US-RW-04: Create Branch from Checkpoint
+**As a** developer
+**I want to** create a git branch from any checkpoint
+**So that** I can preserve or share a specific point in development
+
+**Acceptance Criteria:**
+- Can specify branch name
+- Branch is created at checkpoint's commit
+- Can optionally checkout the new branch
+- Works even if task is completed
+- Branch is visible in git
+
+## Epic: CLI Integration
+
+### US-CLI-01: View History via CLI
+**As a** developer using the terminal
+**I want to** view contract and task history via CLI
+**So that** I can understand project history without opening the web UI
+
+**Acceptance Criteria:**
+- `makima contract history` shows timeline
+- `makima task history` shows conversation
+- `makima task checkpoints` lists checkpoints
+- `makima task checkpoint-diff` shows code changes
+- Output is formatted for terminal readability
+
+### US-CLI-02: Resume via CLI
+**As a** developer using the terminal
+**I want to** resume supervisors and tasks via CLI
+**So that** I can recover from interruptions without the web UI
+
+**Acceptance Criteria:**
+- `makima supervisor resume` resumes supervisor
+- `makima task resume` resumes interrupted task
+- `makima task resume-from` resumes from checkpoint
+- Can specify resume options via flags
+- Clear feedback on resume success/failure
+
+### US-CLI-03: Rewind via CLI
+**As a** developer using the terminal
+**I want to** perform rewind operations via CLI
+**So that** I can quickly undo changes or fork without the web UI
+
+**Acceptance Criteria:**
+- `makima task rewind` rewinds code
+- `makima supervisor rewind-conversation` rewinds conversation
+- `makima task fork` creates fork from history
+- Can specify options via flags
+- Confirmation required for destructive operations
+
+## Epic: Frontend Integration
+
+### US-FE-01: History Timeline UI
+**As a** developer using the web interface
+**I want to** see a visual timeline of contract activities
+**So that** I can quickly understand project progression
+
+**Acceptance Criteria:**
+- Timeline is visually clear and scrollable
+- Events are color-coded by type
+- Can click events for details
+- Can filter and search
+- Responsive on different screen sizes
+
+### US-FE-02: Conversation Viewer UI
+**As a** developer using the web interface
+**I want to** view conversations in a chat-like interface
+**So that** I can easily read and understand AI interactions
+
+**Acceptance Criteria:**
+- Messages are displayed in chat format
+- Different message types are visually distinct
+- Code blocks have syntax highlighting
+- Tool calls are collapsible
+- Can copy message content
+
+### US-FE-03: Checkpoint Browser UI
+**As a** developer using the web interface
+**I want to** browse and interact with checkpoints
+**So that** I can review, restore, or branch from any point
+
+**Acceptance Criteria:**
+- Checkpoints listed with details
+- Can view diff for each checkpoint
+- Can trigger rewind from UI
+- Can create branch from UI
+- Can resume from checkpoint via UI
+
+### US-FE-04: Rewind Controls UI
+**As a** developer using the web interface
+**I want to** easily rewind code or conversation
+**So that** I can undo changes with clear visual feedback
+
+**Acceptance Criteria:**
+- Clear controls for rewind operations
+- Preview of what will be affected
+- Confirmation dialog for destructive actions
+- Progress indication during operation
+- Clear success/failure feedback