feat(settings): the codeman agent skill is on by default

agentSkillEnabled now reads an absent key as ON, the way
workspaceHooksEnabled does: only an explicit false turns it off. A new
session therefore finds the codeman skill in its folder without a
setting first, and with it the verbs that hand work to other CLIs and to
the local model on this Mac. Settings shows the switch on for the same
absent key.

The injection itself is unchanged: add-only, marker-owned, never through
a symlink, never for remote sessions or a plain shell. Turning the
setting off still removes nothing already written.

The quick-start test now pins the new default (injected on an absent
key, nothing after an explicit false), and the docs that said "default
off" say when that changed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/wiki/Settings-Reference.md

@@ -222,7 +222,7 @@ on. Details: [Custom Model Endpoints](Custom-Model-Endpoints#a-model-that-runs-o
 | Ralph / Todo Tracker             | Enables the Ralph loop surfaces.                                                               |
 | Agent Teams                      | Experimental teams. Also needs the CLI's own environment flag.                                 |
 | Pin tab names on the CLI         | Launches every Claude session with `--name` set to its tab name, so Claude Code's prompt label and `/resume` list match your tabs. Claude then stops generating its own titles for those sessions, and a rename in Codeman holds only until the next turn. Synced, off by default; applies from the next session start or respawn. |
-| Codeman Agent Skill              | Under **All agent CLIs**. Injects the agent skill into each new session's case, where that session's CLI looks for skills (every CLI except Pi and a plain shell). Off by default. See [The Codeman Skill](Codeman-Skill). |
+| Codeman Agent Skill              | Under **All agent CLIs**. Injects the agent skill into each new session's case, where that session's CLI looks for skills (every CLI except Pi and a plain shell). On by default since 1.50.0; turn it off to keep the skill out of new sessions' folders. See [The Codeman Skill](Codeman-Skill). |
 | Remote auto-reconnect            | Reattaches dropped remote SSH sessions. On by default.                                         |
 | Nice priority / value            | Runs agent processes at a lower CPU priority.                                                  |
 | Default Codex model              | Model for new local Codex sessions; empty uses Codex's own config. Letters, digits, `.` `_` `-` `/` only. |