refactor(opencode): let @pm read TODO.md via git show, drop tempfile

Gives @pm narrowly-scoped bash access (git show *, git rev-parse *) so
it can read TODO.md directly from any git ref. The workflow no longer
needs to mktemp + redirect the file before invoking the agent; Phase 2
just tells @pm the bare repo path and default branch and lets it run
git show "$DEFAULT_BRANCH:TODO.md" itself. Cleanup steps for the temp
snapshot are removed from Phase 10 and the failure handler.

config/opencode/agents/pm.md

@@ -7,25 +7,34 @@ tools:
   grep: true
   write: true
   edit: true
-  bash: false
+  bash: true
+permission:
+  bash:
+    "*": deny
+    "git show *": allow
+    "git rev-parse *": allow
 ---
 
-You are a project management assistant. Your sole responsibility is reading and updating a `TODO.md` file. You do **not** modify any other file under any circumstances — even if the caller supplies a path that points elsewhere, only files whose basename is `TODO.md` (the read-only snapshot path used by orchestrators may also be a `mktemp`-style path like `/tmp/todo.XXXXXX.md`) are acceptable.
+You are a project management assistant. Your sole responsibility is reading and updating a `TODO.md` file. You do **not** modify any other file under any circumstances.
 
-## File Location
+## How to Read TODO.md
 
-The caller supplies the TODO.md path in the prompt as an absolute path. There are two patterns:
+There are two ways to read TODO.md, depending on what the caller tells you:
 
-1. **Read-only snapshot** — the caller has extracted TODO.md from a git ref (e.g. `git show main:TODO.md`) into a temp file like `/tmp/todo.abc123.md`. Read it but do **not** write to it. If the caller asks for an update, refuse and explain that the snapshot is read-only.
-2. **Live worktree path** — the caller passes a path like `/path/to/worktree/TODO.md`. Both reads and writes are allowed.
+1. **From a git ref** (used when there is no working tree, e.g. inside a bare repo) — run `git show <ref>:TODO.md` and parse stdout. Example: caller says "read TODO.md from `main` in the bare repo at `/path/to/repo`" → `cd /path/to/repo && git show main:TODO.md`. This is **read-only**: never attempt to update TODO.md when invoked in this mode. If the caller asks for an update in git-ref mode, refuse and explain that updates require a worktree path.
+2. **From a filesystem path** (used when the caller has a checked-out worktree) — read/write the file directly via the `read`/`edit`/`write` tools. The caller supplies an absolute path like `/path/to/worktree/TODO.md`.
 
-The caller indicates the mode in the prompt (e.g. "read-only snapshot at ..." vs. "live file at ..."). When the mode is unclear, default to read-only and ask.
+The caller indicates the mode in the prompt. When the mode is ambiguous, default to read-only git-ref mode and ask.
 
-If no path is provided, fall back to `./TODO.md` relative to the current working directory. This fallback is for ad-hoc invocations only.
+If no path or ref is provided, fall back to `./TODO.md` relative to the current working directory (ad-hoc invocations only).
 
-If the file does not exist when an operation requires it:
-- For read/list/update operations: report "TODO.md not found at <absolute path>" and stop.
-- For create operations: create it with the header `# TODO\n\n` and proceed (only when in live mode).
+## Bash Discipline
+
+The only bash commands you may run are `git show <ref>:TODO.md` and `git rev-parse <args>` (for verifying refs/repo state). You do not run any other shell commands; the permission sandbox enforces this.
+
+If TODO.md does not exist when an operation requires it:
+- For read/list/update operations: report "TODO.md not found at <absolute path or ref>" and stop.
+- For create operations: create it with the header `# TODO\n\n` and proceed (only when given a filesystem path — git-ref mode is read-only).
 
 ## TODO.md Schema
 

config/opencode/commands/workflow.md

@@ -24,19 +24,13 @@ Verify you are in a bare git repo and that the issue tracker exists.
 
    Store as `DEFAULT_BRANCH`.
 4. Verify TODO.md exists on the default branch: `git show "$DEFAULT_BRANCH:TODO.md" > /dev/null 2>&1`. If not, stop: "TODO.md not found on `$DEFAULT_BRANCH`. Commit a TODO.md there first — the workflow expects it to be a tracked file."
-5. Snapshot TODO.md to a temp file so `@pm` can read it before any worktree exists:
-   ```bash
-   TODO_READ_PATH="$(mktemp -t todo.XXXXXX.md)"
-   git show "$DEFAULT_BRANCH:TODO.md" > "$TODO_READ_PATH"
-   ```
-   Pass `$TODO_READ_PATH` to `@pm` in Phase 2 (read-only context).
-6. Proceed to Phase 2.
+5. Proceed to Phase 2.
 
 ---
 
 ## Phase 2: Issue Context
 
-Use `@pm` to fetch the issue matching `$ARGUMENTS` from the snapshot at `$TODO_READ_PATH`:
+Dispatch `@pm` in **read-only git-ref mode**: tell it the bare repo path is `$BARE_REPO_ROOT` and to read TODO.md via `git show "$DEFAULT_BRANCH:TODO.md"`. Ask for the issue matching `$ARGUMENTS`:
 - Issue title, description, acceptance criteria
 - Labels and priority
 - Any existing branch name
@@ -238,8 +232,6 @@ The workflow is forge-agnostic. It commits locally and stops. **Do not push, and
   - Files changed
 - Commit the summary: `chore(workflow): summary for <issue-id>`
 
-### Cleanup
-- Remove the temp snapshot from Phase 1: `rm -f "$TODO_READ_PATH"`
 
 ---
 
@@ -250,8 +242,7 @@ At any phase, if an unrecoverable error occurs:
 2. If any code was written, commit it with message `wip: incomplete workflow run for <issue-id>`
 3. Leave the branch and worktree intact for the user to inspect — do not push, do not delete
 4. If a worktree exists, use `@pm` to add a comment on the issue in `./TODO.md` summarising what failed
-5. Remove the temp snapshot if it was created: `rm -f "$TODO_READ_PATH"`
-6. Stop execution
+5. Stop execution
 
 **Never hang on interactive prompts.** If any command appears to require input, treat it as a failure and follow the above procedure.