docs(web-ui/dashboard): fix missing /api/ prefix on reminder endpoints

/cancel-reminder/{id} and /retry-reminder/{id} were documented without
the /api/ prefix in two places (SCH3DUL3S tab prose + endpoint list).
The actual routes (hive-c0re/src/dashboard.rs) and the frontend JS
(tabs.js) both use /api/cancel-reminder/ and /api/retry-reminder/.

docs/web-ui/dashboard.md

@@ -430,9 +430,9 @@ Refreshed on tab activation and after each submit/cancel. Backed by
 **QU3U3D R3M1ND3RS** — reminders agents have scheduled for
 themselves (via the `remind` tool) but not yet delivered.
 Each row shows the owner, due time, and message; a `CANC3L`
-button hard-deletes (`POST /cancel-reminder/{id}`) and a
+button hard-deletes (`POST /api/cancel-reminder/{id}`) and a
 `R3TRY` button re-arms one whose delivery failed
-(`POST /retry-reminder/{id}`). Backed by `GET /api/reminders`.
+(`POST /api/retry-reminder/{id}`). Backed by `GET /api/reminders`.
 Lives in the SCH3DUL3S tab alongside operator schedules so the
 operator has one place for everything time-fired. The due-time
 label (`.reminder-due`) carries a `data-due-at` Unix timestamp
@@ -1124,8 +1124,8 @@ that's a browser-level decision, not ours.
   a background `du -sxb` of the agent's state dir + container writable
   rootfs every ~5 min, `-x` excluding the shared read-only nix store.
   `null` until the first sample lands.
-- `POST /cancel-reminder/{id}` — hard-delete a pending reminder.
-- `POST /retry-reminder/{id}` — re-arm a reminder whose delivery
+- `POST /api/cancel-reminder/{id}` — hard-delete a pending reminder.
+- `POST /api/retry-reminder/{id}` — re-arm a reminder whose delivery
   failed (clears the failure state so the scheduler retries).
 - `GET /api/tool-groups` — returns `{ groups: Vec<String>,
   assignments: BTreeMap<String, Vec<String>>,