Honor chamber.config default_base + hooks for EnterWorktree-created worktrees

[echochamber]

Summary

Fixes #1. Claude Code's built-in EnterWorktree tool (which ~/.claude/CLAUDE.md tells agents to prefer) creates worktrees from its own worktree.baseRef (default fresh = origin/<default-branch> = main) and ignores .claude/chamber.config — so it skips the per-repo default_base, post-create hooks, and symlink_files. In manabot-alpha (default_base: origin/dev, PRs target dev), every EnterWorktree branch was based on main, polluting PRs with ~25 dev→main promotion merges, and deps were never installed.

Root cause confirmed empirically: an existing EnterWorktree worktree (worktree-worker-egress-step1-vpc) was based exactly on origin/main's tip, 25 commits ahead of origin/dev.

Fix

New PostToolUse hook on EnterWorktree: wtutils/enterworktree-reconcile.sh. After the tool creates the worktree it:

1. Re-bases the new branch onto chamber.config default_base (e.g. origin/dev) — via git reset --hard — only for a freshly-created empty worktree.
2. Runs the chamber post-create hooks + applies symlink_files/symlink_dirs/beads redirect, reusing wtutils.sh's wt--setup-worktree (no config-parsing duplication).

EnterWorktree's baseRef can't target an arbitrary branch, so this is a post-create reconciliation, exactly as the issue suggested.

Safety (runs on every EnterWorktree create)

The rebase is gated hard — it proceeds only when all hold:

• chamber.config declares a default_base
• the worktree tree is clean (no staged/unstaged/untracked)
• HEAD has no commits of its own beyond the base it was cut from (HEAD reachable from origin/<default-branch>)
• default_base resolves to a real commit differing from HEAD

If any gate fails: no history touched — setup hooks still run (idempotent), and a skip reason is logged to ~/.claude/hooks/enterworktree-reconcile.log. The hook never blocks Claude (all paths exit 0). The wt-add shell path is untouched.

How it was tested

/tmp/claude-safe/test-reconcile.sh builds throwaway repos (main ahead of dev by promotion merges, mimicking manabot-alpha) and pipes a PostToolUse payload into the hook. 13 assertions across 6 scenarios, all pass:

• (a) empty main-based worktree → rebased to origin/dev, 0 commits ahead of dev (clean PR)
• (b) post-create hooks ran + symlink_files applied
• (c) dirty worktree → HEAD untouched, refusal logged
• (d) worktree with a committed change → HEAD untouched, work commit preserved
• (e) no default_base → no rebase, setup still runs
• idempotent when already on default_base; stable on re-run

shellcheck clean on the hook and install.sh.

Deploy / sync

The repo does not edit the user's settings.json. To deploy:

1. cd ~/Code/chaimber-cliutils && ./install.sh — symlinks the hook into ~/.claude/hooks/ and prints the registration snippet.
2. Register it in ~/.claude/settings.json under .hooks.PostToolUse. There is already an EnterWorktree|ExitWorktree matcher object running worktree-cwd-notify.sh; the simplest path is to append to that object's hooks array:

{ "type": "command", "command": "bash ~/.claude/hooks/enterworktree-reconcile.sh" }

(or add a standalone { "matcher": "EnterWorktree", "hooks": [...] } object — order doesn't matter).

Open questions / notes

• I did not modify live ~/.claude/ files — review then run install.sh + the settings.json edit yourself.
• Stale, unrelated finding: ~/.claude/hooks/worktree-create.sh / worktree-remove.sh reference wt--is-excluded + ~/.claude/chamber.user.config, which no longer exist in wtutils.sh. Those hooks are also not wired into settings.json and only run outside a git repo anyway, so they're effectively dead for git repos. Out of scope here; flagging for cleanup.

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