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.

apps/desktop/src/app/session/hooks/use-session-actions.ts

@@ -763,7 +763,7 @@ export function useSessionActions({
           await requestGateway('session.close', { session_id: closingRuntimeId }).catch(() => undefined)
         }
 
-        await deleteSession(storedSessionId)
+        await deleteSession(storedSessionId, removed?.profile)
         clearQueuedPrompts(storedSessionId)
 
         if (closingRuntimeId) {
@@ -839,7 +839,7 @@ export function useSessionActions({
       }
 
       try {
-        await setSessionArchived(storedSessionId, true)
+        await setSessionArchived(storedSessionId, true, archived?.profile)
         notify({ durationMs: 2_000, kind: 'success', message: 'Archived' })
       } catch (err) {
         if (archived) {