feat: implement repository clone mode with SSH key support

- Add clone_mode and branch fields to tool_instances
- Add ssh_key_id to git_repositories for per-repo SSH key assignment
- Implement host-side git cloning with branch selection (default: main)
- Mount SSH keys into containers for git operations in clone mode
- Add dirty state check on clone-mode instance deletion with confirmation
- Update SessionsPage with mount/clone selector, branch input, SSH key display
- Add SSH key selector to repository creation form
- Add dirty delete confirmation modal with changed files list
- Update API schemas and endpoints for new fields
- Sync delta specs to main specs (git-repo, tool-instances, repo-clone-mode)
- Archive completed OpenSpec change: repo-clone-mode-with-ssh
- Document git requirement for custom tool types

Quality gates: Frontend typecheck and build passed
OpenSpec: repo-clone-mode-with-ssh archived with all tasks complete

openspec/changes/archive/2026-05-22-ui-redesign-home-settings/design.md

@@ -0,0 +1,98 @@
+# UI Redesign - Design
+
+## Information Architecture
+
+```
+App
+├── Home
+│   ├── Hero / status
+│   ├── Open sessions
+│   ├── Available projects
+│   └── Session creation
+├── Sessions
+├── Projects
+├── Tool Workshop
+├── Settings
+│   ├── General
+│   └── SSH Keys
+└── Legacy routes
+    └── Redirect to new locations
+```
+
+## Home Page
+
+### Purpose
+
+Provide a fast, glanceable overview of the user's active work.
+
+### Sections
+
+1. **Hero**
+   - Greeting
+   - Short status line
+   - Primary actions: New Project, Open Session, Settings
+
+2. **Summary strip**
+   - Small count cards for sessions, projects, and tooling state
+
+3. **Open Sessions**
+   - Primary section
+   - Session cards with project, repository, tool type, status, and actions
+
+4. **Available Projects**
+   - Secondary section
+   - Project cards with quick entry into the project workspace
+
+5. **Session composer**
+   - Optional compact create flow if it fits the page cleanly
+
+## Settings Page
+
+### Layout
+
+Tabbed shell with one content area and two tabs:
+
+- General
+- SSH Keys
+
+### Tab Responsibilities
+
+**General**
+- Theme
+- Git identity
+- Default editor
+
+**SSH Keys**
+- List keys
+- Create key
+- Copy public key
+- Delete key
+
+**Tool Types and Tool Configs**
+- Moved to Tool Workshop page (`/tool-workshop`)
+- Centralized tool management with split-pane UI
+
+## Visual Direction
+
+- Font: Inter for UI text
+- Code font: monospace only for technical fields
+- Palette: warm light surfaces, forest green primary, muted utility accents
+- Dark mode: charcoal surfaces with softened accents
+- Styling: editorial, structured, high-contrast hierarchy, minimal chrome
+
+## Routing
+
+- `/` -> Home
+- `/sessions` -> Sessions page (kept as top-level navigation)
+- `/settings` -> General tab
+- `/settings/ssh-keys` -> SSH Keys tab
+- `/tool-workshop` -> Tool Workshop (replaces settings tabs for tool management)
+- legacy `/ssh-keys` -> redirect to settings tab
+- legacy `/tool-types`, `/tool-configs` -> redirect to tool-workshop
+
+## Component Strategy
+
+- Reuse shell and existing APIs
+- Replace the dashboard page with the new home overview
+- Convert the settings layout into a shared tab shell
+- Keep changes focused to the frontend layer