refactor(cli): one watch loop, and pin the ScopeArgs boundary (#10596)

* refactor(cli): one watch loop, and pin the ScopeArgs boundary

#10315 — extract the poll loop `activity watch` and `runs watch` each had
a copy of into `commands/utils/watch.rs`, generic over the polled item so
each command keeps its own domain model, output schema, and terminality
rule. Both command names and both wire shapes are unchanged. Fixes the
live defect #10538 surfaced: `activity watch --notify` built its event
with `transport: None, route: None` and never read the bound route, so
`--notification-route` was silently dropped by that command alone.

Aligns `triage --poll-interval` to `--interval`, keeping `--poll-interval`
as a visible alias. Both args are `global = true` within `triage` only, so
neither the root global-flag surface nor the rendered `--help` the Lab
recovery handshake parses is affected.

#10312 — the five commands #10510 deferred all stay deferred, now with
executable reasons in `commands/utils/scope_boundary_tests.rs` instead of
prose in a merged PR body, plus a structural pin that confines hand-rolled
six-way entity selection to `deploy`.

Refs #10312, #10315.

* docs(cli): regenerate the CLI reference tree

Pre-existing drift, not from this branch. #10562 deleted `runs retention`
and re-worded the retention flag help on `runs artifact cleanup-persisted`,
`self cleanup-runtime-tmp`, `runner slots prune`, and `runner workspace
prune`; it landed alongside #10563, which introduced the generated tree,
without regenerating it. The CLI Reference Docs gate has been red on every
homeboy-cli PR since.

Taken verbatim from the gate's own `cli-reference-docs` artifact. Nothing
in this diff comes from this branch's changes — `activity.md` and
`triage.md` are byte-identical, because `triage`'s renamed `--interval` is
`global = true` and generated pages exclude globals by design.

---------

Co-authored-by: chubes-bot <266378653+homeboy-ci[bot]@users.noreply.github.com>

Author: chubes4