docs(custom-model): bring CLAUDE.md and api-reference.md up to date

Full documentation review pass across the branch's 30 commits.
CLAUDE.md's Custom Model Endpoint Profiles entry hadn't been touched
since the initial backend+picker cut (3 early commits) despite 27
follow-up commits adding real behavior — it described restart-in-place
as universal (now claude-only; 7 other CLIs launch one-shot) and
claimed codex's Responses-API gap as a flat protocol break (now
re-verified as a more precise tool-calling gap). Corrected both and
added a new paragraph covering everything landed since: the llama-swap
conflict check, the after-the-fact swap-displacement sweep, the
/running-cmd-based context-length fix, the context-window floor
warning, skipFirstRunPrompts, the real-time /api/events-based log
status, and the countdown-to-Cancel-button change.

docs/api-reference.md's custom-model-endpoints section was missing the
running-status route, the requiresConfirmation/requiresContextWarning
response shapes, and POST /api/quick-start's customModel field
entirely (the primary launch path for 7 of 8 supported CLIs) — added
all three. Also fixed a real markdown bug in custom-model-endpoints.md:
an inline code span (`POST <baseUrl>/v1/chat/completions`) split across
a line break, which CommonMark renders with the line ending collapsed
to a space, so it displayed as ".../v1/chat/ completions" with a
spurious space inside the path.

Verified: origin/master and upstream/master are both already an
ancestor of this branch (identical at bd286bf5, no new commits since
this branch was cut) — nothing to merge, no conflicts.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RqZeHrRS6DYcGcGX2p9EwG

docs/custom-model-endpoints.md

@@ -12,11 +12,12 @@ recipe confidence table, and security reasoning:
 [`custom-model-endpoints-plan.md`](custom-model-endpoints-plan.md).
 
 > **Status**: fully wired end to end — registry capability, the injection
-> engine, the endpoint store + discovery route, the session restart route,
-> a settings-panel CRUD surface, and the Run-menu picker described below.
-> Antigravity has no known custom-endpoint mechanism and is not supported.
-> The HTTP API (examples below) still works directly and is what the picker
-> itself calls under the hood.
+> engine, the endpoint store + discovery route, both the restart-in-place
+> apply route (Claude) and the one-shot quick-start launch path (every
+> other supported harness), a settings-panel CRUD surface, and the Run-menu
+> picker described below. Antigravity has no known custom-endpoint
+> mechanism and is not supported. The HTTP API (examples below) still works
+> directly and is what the picker itself calls under the hood.
 
 ## Turning it on
 
@@ -351,8 +352,9 @@ which can take anywhere from a few seconds to well over a minute:
   naming the model, and confirmed live: applying a selection alone never
   reached llama-swap at all (nothing in its own server logs), since nothing
   had actually asked it to load anything yet. Both apply routes now also
-  send the smallest real request that will — `POST <baseUrl>/v1/chat/
-completions` with `max_tokens: 1` and one throwaway message — whenever the
+  send the smallest real request that will —
+  `POST <baseUrl>/v1/chat/completions` with `max_tokens: 1` and one
+  throwaway message — whenever the
   target model isn't already the one loaded and ready, fire-and-forget (its
   response is never read; `GET /api/model-endpoints/:id/running-status`,
   polled client-side, is what actually confirms readiness). The response