fix(pi): read pi's composer rule so a pi turn can end

A pi session stayed "working" for good once a turn started. pi's braille
spinner trips the SPINNER_PATTERN fast path, which marks the pane working,
but only a composer glyph arms the idle confirmation and pi declared none,
so it fell back to Claude's `❯`, which pi never draws. Measured on beta136:
an errored turn stayed busy/isWorking for 3+ minutes after pi was back at
rest.

pi has no composer glyph. Measured on a live pi 1.1.0 pane (capture-pane
every 250 ms through a turn): its composer sits between two `─` rules, and
while a turn runs it rewrites the top rule as `── ⠏ Working ───` on every
frame. The registry entry now names the rule as the glyph that arms the
check and a spinner frame inside it as the working line.

The same glyph settles a reattached pi pane (a restored pane gets no launch
timer): tmux's reattach repaint carries `─`, which arms the confirmation.
The submit verifier reads the last rule, finds no prompt text and stands
down, so it can never press Enter on a pi pane.

Verified on an isolated instance from this branch: a real pi turn emitted
session:working then session:idle, and after a server restart the restored
pi pane went busy -> idle in about 3 s.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/pi-integration.md

@@ -223,9 +223,13 @@ command override instead.
 ## Known gaps
 
 - **No idle/completion hook.** Pi has no hook system Codeman can install into, so
-  idle detection falls back to output-stabilization like the other external CLIs.
-  Pi 0.84.0 shipped an `agent_settled` extension event that is a genuine idle
-  signal; a Codeman pi extension using it is the highest-value follow-up.
+  idle detection reads the screen: the registry entry's `workDetect` names pi's
+  composer rule (`─`) as the glyph that arms the idle check and the spinner pi embeds
+  in that rule while a turn runs (`── ⠏ Working ───`) as the working line, measured
+  on pi 1.1.0. Without it a pi session that had started a turn never left `busy`,
+  since pi never draws Claude's `❯`. Pi 0.84.0 shipped an `agent_settled` extension
+  event that is a genuine idle signal; a Codeman pi extension using it is still the
+  highest-value follow-up.
 - **No response viewer.** Pi writes JSONL v3 session files under
   `~/.pi/agent/sessions/`; nothing reads them yet.
 - **Cron jobs mis-detect readiness.** The cron readiness poll looks for `❯` or a

docs/wiki/Agent-CLIs.md

@@ -69,7 +69,7 @@ output. The other CLIs expose no equivalent.
 | Respawn cycling and unattended runs               | Yes    | Yes                                                  |
 | Cron jobs                                         | Yes    | Yes                                                  |
 | Docker cases, remote SSH cases                    | Yes    | Yes                                                  |
-| Precise idle detection                            | Yes    | Codex: same screen check, via its own prompt and working line. DeepSeek: reports its state itself. Others: output stabilization, coarser |
+| Precise idle detection                            | Yes    | Codex and Pi: same screen check, via their own prompt and working line. DeepSeek: reports its state itself. Others: output stabilization, coarser |
 | Auto-resume when a usage limit resets             | Yes    | No                                                   |
 | Plan usage chip                                   | Yes    | No                                                   |
 | Approvals Inbox                                   | Yes    | DeepSeek yes; others no                              |
@@ -169,6 +169,10 @@ Pi needs the opposite instincts from every other CLI here.
   `HF_TOKEN`, and so on) share no common prefix, and the environment allowlist is global
   rather than per mode, so admitting them for Pi would widen the allowlist for every mode at
   once. They stay out.
+- **Work detection reads Pi's composer rule.** Pi has no prompt glyph; while a turn runs it
+  puts a spinner into the rule above the composer (`── ⠏ Working ───`), and Codeman reads
+  that to tell working from idle. Before 1.36.0 a Pi session that had started a turn showed
+  as working for good.
 
 Guide: [`docs/pi-integration.md`](https://github.com/Ark0N/Codeman/blob/master/docs/pi-integration.md).