update CLAUDE.md to reflect Commander 14, new vm/open/squash/merge behaviors, binary caching, and container provisioning details

CLAUDE.md

@@ -10,7 +10,7 @@
 
 - **Runtime**: [Bun](https://bun.sh) (not Node.js — use `bun` for everything)
 - **Language**: TypeScript (strict, ESNext, bundler module resolution)
-- **CLI parsing**: [Commander.js](https://github.com/tj/commander.js) 13.x
+- **CLI parsing**: [Commander.js](https://github.com/tj/commander.js) 14.x
 - **Containers**: Apple Container (`brew install container`)
 - **Entry point**: `src/cli.ts` (shebang: `#!/usr/bin/env bun`, runs directly without compilation)
 
@@ -38,22 +38,24 @@ src/
   spinner.ts    # CLI progress spinner (braille frames)
   commands/
     new.ts      # Create session, derive branch name from prompt
-    open.ts     # Re-enter existing session
+    open.ts     # Re-enter existing session (always uses --continue)
     close.ts    # Remove worktree and clean up session
     list.ts     # Show all active sessions with status
     save.ts     # Stage all changes and commit
     merge.ts    # Merge branch into main with conflict resolution
+    squash.ts   # Squash-merge branch into main (AI commit message) and close
     rebase.ts   # Rebase branch onto main with conflict resolution
     review.ts   # Launch grumpy code review with Claude
     diff.ts     # Show uncommitted changes or full branch diff
     show.ts     # Show prompt and full diff for a branch
     log.ts      # Show commits on branch not on main
     dir.ts      # Print worktree path for a session
+    edit.ts     # Open a session file in $EDITOR (with path escape check)
     shell.ts    # Open fish shell in container
     cleanup.ts  # Remove stale sessions
-    vm.ts       # VM subcommands (create, start, stop, destroy, status, info)
+    vm.ts       # VM subcommands (create, start, stop, destroy, status, info, uncache)
     completions.ts  # Fish shell completions generator
-    helpers.ts  # Shared: requireSession, resolveConflicts, saveChanges
+    helpers.ts  # Shared: requireSession, resolveConflicts, mergeAndClose, saveChanges
 ```
 
 ## Architecture
@@ -77,11 +79,15 @@ Each module has a single responsibility. No classes — only exported async func
 
 - Image: `ubuntu:24.04`
 - User: `ubuntu`
-- Mounts: `~/dev` and `~/.sandlot` from host
+- Memory limit: 4G
-- Provisioned once on first use: installs `curl git neofetch fish unzip`, Bun, Claude Code, git identity, API key helper, activity tracking hook
+- Mounts: `~/dev` **read-only** at `/host`, `~/.sandlot` read-write at `/sandlot`
+- Host symlinks: creates `~/dev` → `/host` and `~/.sandlot` → `/sandlot` inside the container so host-absolute worktree paths resolve correctly
+- `containerPath()` in `vm.ts` translates host paths to container paths (`~/.sandlot/…` → `/sandlot/…`, `~/dev/…` → `/host/…`)
+- Provisioned once on first use: apt installs `curl git fish unzip`, then installs Bun, Claude Code, neofetch, and Neovim
+- Binary caching: after first install, binaries are cached in `~/.sandlot/.cache/` (bun, claude, neofetch, nvim.tar.gz) — subsequent `vm create` uses cached copies, skipping downloads
 - API key: read from `~/.env` on host (`ANTHROPIC_API_KEY=...`), written to a temp file and copied as `~/.claude/api-key-helper.sh` in the container (never passed as a process argument)
 - Claude settings: `skipDangerousModePermissionPrompt: true`, activity tracking hooks (`UserPromptSubmit` / `Stop`) in container
-- Also writes `~/.claude.json` with `hasCompletedOnboarding: true` to skip first-run prompts
+- Also writes `~/.claude.json` with `hasCompletedOnboarding: true` and `effortCalloutDismissed: true`
 
 ## Shell Command Pattern
 
@@ -131,12 +137,20 @@ Always use `.nothrow()` for commands that may fail non-fatally. Use `.quiet()` t
 
 - `vm.exec()` prepends `export PATH=$HOME/.local/bin:$PATH` so `claude` binary is found
 - `vm.claude()` uses `Bun.spawn` with `stdin/stdout/stderr: "inherit"` for interactive TTY; in print mode (`-p`), captures stdout via pipe and returns the output
+- `vm.claude()` runs Claude with `--dangerously-skip-permissions`, `--model claude-opus-4-6`, and `--append-system-prompt` (system prompt describes the container environment)
+- `vm.claude()` retry logic: if exit code is non-zero and `--continue` was used, retries without `--continue`
 - `vm.claudePipe()` writes input to a temp file in `~/.sandlot/`, pipes it to `claude -p` inside the container, and returns the result — used for commit message generation and conflict resolution
 - `vm.isClaudeActive()` reads activity marker files written by the in-container `sandlot-activity` hook script
 - Branch creation in `createWorktree()` handles three cases: local branch, remote branch (tracks origin), new branch from HEAD
 - `sandlot new` accepts a prompt instead of a branch name — derives a 2-word branch name via the Anthropic API (Haiku), falling back to simple text munging
+- `sandlot open` always passes `continue: true` to `vm.claude()` to resume the previous conversation
 - `sandlot save` uses `vm.claudePipe()` to generate commit messages from the staged diff
-- `sandlot merge` and `sandlot rebase` use `vm.claudePipe()` to resolve merge conflicts automatically
+- `sandlot merge`, `sandlot squash`, and `sandlot rebase` use `vm.claudePipe()` to resolve merge conflicts automatically
+- `sandlot squash` generates an AI commit message for the squash commit via `claudePipe()`; falls back to `"squash <branch>"`
+- `sandlot merge` and `sandlot squash` both delegate to `mergeAndClose()` in `helpers.ts`, which merges, resolves conflicts, commits, and then calls `closeAction()` to clean up
+- `sandlot list` discovers missing session prompts by parsing Claude's `history.jsonl` from inside the container
+- `sandlot list` shows four status icons: idle (dim `◌`), active (cyan `◯`), dirty/unsaved (yellow `◎`), saved (green `●`)
 - `sandlot new` and `sandlot open` auto-save changes when Claude exits (disable with `--no-save`)
-- Default behavior (no subcommand): shows `list` if sessions exist, otherwise shows help
+- `sandlot close` has a hidden `rm` alias
+- Default behavior (no subcommand): always runs `list` (which prints "No active sessions." if empty)
 - `.sandlot/` should be in the repo's `.gitignore`