Add handler-quiet-output to the built-in skills

Agents narrate far more than anyone reads: the transcript is not the
deliverable, and prose there is spent tokens burying information where
no one looks. The new skill routes each kind of output to its store —
work happens through tool calls; a minimized NOTES.md ledger (one
bullet per action, committed with the work) records what happened and
how; problems and causes go to memory; status goes to the final
checkpoint-sized message the Stop hook captures onto the checkmark; and
questions go through the question tool, which reaches the operator as a
push notification and an answer prompt in the web and mobile apps
instead of stalling silently in the transcript.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01731mKtVzsfeT4Vi3TvkR48

README.md

@@ -335,7 +335,8 @@ What the dashboard can now do (all state-changing actions require `ADMIN_TOKEN`)
   choices a human would be asked — always user scope, the instructions' defaults — and
   reports them in the command result for after-the-fact review.
 - **Built-in operator skills** ship with Handler and are seeded into the managed store
-  on API startup (`handler.builtin_skills`): gate recovery, testing standard,
+  on API startup (`handler.builtin_skills`): quiet output (tool calls + a minimized
+  `NOTES.md` ledger instead of transcript prose), gate recovery, testing standard,
   checkpoint quality, memory discipline, mise-task rules, scheduled-run continuity,
   and secrets hygiene — the judgment layer the hard gates can't enforce. Seeding is
   idempotent by name, so operator edits and disables survive upgrades; deleting one