fix(desktop): route remote-profile session mutations + fix unified-list pagination

Follow-up to the read-routing fix: make remote-profile sessions fully
first-class, not just resumable.

Mutations (rename/archive/delete) went through the same hermes:api handler but
never carried the owning profile, so they hit the local primary's state.db --
which has no row for a remote session. Deleting/archiving/renaming a remote
session silently no-op'd or 404'd, and the row reappeared on next refresh.

- hermes.ts: setSessionArchived/deleteSession/renameSession take the owning
  profile and pass it as request.profile so Electron routes to that profile's
  backend (matching the read path). Callers now forward session.profile.
- main.cjs: generalize the intercept (read -> request) to also reroute
  DELETE/PATCH on /api/sessions/{id} for remote profiles, stripping the profile
  param (the remote serves its own state.db; no cross-profile semantics there).
- web_server.py: DELETE /api/sessions/{id} gains a profile param for parity with
  GET/PATCH (local cross-profile delete).

Also fix the unified-list merge: it concatenated each remote's page onto the
primary's without re-windowing, so a limit=N request could return up to
N*(1+remotes) rows and report the primary's (stale) total. Now it over-fetches
limit+offset from each remote (from offset 0), re-sorts by recency, re-windows
to the page, and recomputes total/profile_totals from the remote counts.

Verified live against a remote backend: rename/archive/delete mutate the remote
db; page 1 windows to limit, profile_totals reflect remote counts, page 2 has no
overlap with page 1. tsc -b clean; connection-config tests pass.

hermes_cli/web_server.py

@@ -5257,9 +5257,11 @@ async def get_session_messages(session_id: str, profile: Optional[str] = None):
 
 
 @app.delete("/api/sessions/{session_id}")
-async def delete_session_endpoint(session_id: str):
-    from hermes_state import SessionDB
-    db = SessionDB()
+async def delete_session_endpoint(session_id: str, profile: Optional[str] = None):
+    # ``profile`` deletes a session belonging to another (local) profile by
+    # opening its state.db directly. Remote profiles never reach here — the
+    # desktop routes their DELETE to the remote backend. Omit for current/default.
+    db = _open_session_db_for_profile(profile)
     try:
         if not db.delete_session(session_id):
             raise HTTPException(status_code=404, detail="Session not found")