docs: trim implementation detail from the OpenAPI/Swagger doc

mara, PR review: 'less impl details in user facing docs'. Dropped the
utoipa crate link, the ApiDoc source-file pointer, and the
#[utoipa::path(...)] annotation-syntax mention from the Dashboard
endpoints intro paragraph -- kept only what a reader needs (where to
find it, that it's a growing subset not yet the full list). Trimmed
the H0M3-page mention the same way.

docs/web-ui/dashboard.md

@@ -722,9 +722,8 @@ The H0M3 hub is the primary landing page (served at `/` by default). A
 responsive grid of link tiles — Dashboard, Flow, Logs, Matrix (when enabled),
 Forge (when enabled), among others (Builds, Stats, Settings, Core,
 Credentials, API) — each pointing to their respective surfaces. The **API**
-tile is a static link straight to `/api/docs` (the Swagger UI — see
-`## Dashboard endpoints` below), always shown since the endpoint always
-exists (no gating, unlike Matrix/Forge). The page
+tile always shows (unlike Matrix/Forge, see below) and links to the
+Swagger UI at `/api/docs`. The page
 is a pure portal with no tab-bar or SSE subscriptions. Typography + colours
 inherit from the shared theme (Catppuccin Mocha via `common.css` + `theme.css`).
 Optional tiles are hidden until `home.js` confirms their availability:
@@ -1152,16 +1151,10 @@ that's a browser-level decision, not ours.
 
 ## Dashboard endpoints
 
-Also browsable interactively: `hive-c0re` auto-generates an OpenAPI 3
-spec via [`utoipa`](https://docs.rs/utoipa) (`hive-c0re/src/dashboard/
-mod.rs`'s `ApiDoc`), served raw at `GET /api/openapi.json` and as a
-Swagger UI at `/api/docs` — same loopback dashboard port, reachable
-externally through the gateway's `/api/` proxy prefix like the rest of
-this list. It's deliberately incremental: only routes carrying a
-`#[utoipa::path(...)]` annotation appear, so it's not yet a complete
-mirror of the hand-written list below — an unannotated route still
-works, it just doesn't show up in the spec until someone adds the
-annotation. The H0M3 hub's **API** tile links straight to `/api/docs`.
+Also browsable interactively at `/api/docs` (a Swagger UI, linked from
+the H0M3 hub's **API** tile), with the raw spec at `/api/openapi.json`.
+It's a growing supplement, not yet a full replacement for the list
+below — some endpoints aren't in it yet.
 
 - `POST /api/approve/{id}` — approve a pending approval. Fires
   `ApprovalResolved` on the dashboard event channel; client