fix(desktop): preserve current workspace activation seams

Reconcile the multi-workspace agent stack with current main without dropping the authenticated-media redirect boundary, agent-managed profile setting, or shared-compute status publication. Keep the file-size exceptions explicit for the combined state and command wiring.

Co-authored-by: npub12gtutshhh76rx0jx697f32f9tffd4hhp3hx58fp4x6u4uemkm7sqf8f757 <5217c5c2f7bfb4333e46d17c98a9255a52dadee18dcd43a43536b95e6776dfa0@sprout-oss.stage.blox.sqprod.co>
Signed-off-by: npub12gtutshhh76rx0jx697f32f9tffd4hhp3hx58fp4x6u4uemkm7sqf8f757 <5217c5c2f7bfb4333e46d17c98a9255a52dadee18dcd43a43536b95e6776dfa0@sprout-oss.stage.blox.sqprod.co>

desktop/scripts/check-file-sizes.mjs

@@ -374,7 +374,11 @@ const overrides = new Map([
   // +5 (1068 -> 1073): merge with main, which independently added the
   // managed_agent_profile_reconcile_enabled flag (field + doc + init) under
   // its own 1042-line override. Union of two separately approved additions.
-  ["src-tauri/src/app_state.rs", 1054],
+  ["src-tauri/src/app_state.rs", 1090],
+  // lazy-workspace-activation adds seven command/state wiring lines to lib.rs.
+  // Keeping the registration and safety-gate setup together is clearer than a
+  // one-off extraction whose only purpose would be satisfying the line cap.
+  ["src-tauri/src/lib.rs", 1007],
   // multi-slot splitting + no-op suppression (#1309): the ReadStateManager
   // class grew from ~700 lines to ~1019 with the addition of
   // splitContextsIntoBudgetedSlots (pure fn + 5 tests), publishSplitSlots,

desktop/src-tauri/src/app_state.rs

@@ -18,6 +18,15 @@ use crate::managed_agents::ManagedAgentProcess;
 pub struct AppState {
     pub keys: Mutex<Keys>,
     pub http_client: reqwest::Client,
+    /// A no-redirect client for authenticated relay media fetches (download,
+    /// clipboard copy, snapshot, editor). Every caller pre-validates the URL
+    /// origin, but the app-wide `http_client` follows redirects by default, so
+    /// a relay `/media/` URL returning a 3xx to an off-origin or private host
+    /// would forward the minted media Authorization header across origins —
+    /// a redirect-hop SSRF. This client treats any 3xx as a non-success
+    /// response (surfaced as an error) so the auth token never leaves the
+    /// validated relay origin.
+    pub media_fetch_client: reqwest::Client,
     /// Workspace-provided relay URL override. Set by `apply_workspace` on app
     /// init and takes priority over env vars and compile-time defaults.
     pub relay_url_override: Mutex<Option<String>>,
@@ -155,6 +164,27 @@ fn identity_from_env() -> Option<Keys> {
     }
 }
 
+/// Build the no-redirect HTTP client used for authenticated relay media
+/// fetches (download / copy).
+///
+/// This client is a security boundary, not a convenience: it carries a minted
+/// media `Authorization` header, so it MUST NOT follow redirects. A relay 3xx
+/// to an off-origin or private host would otherwise forward that header across
+/// origins (a redirect-hop SSRF). `redirect::Policy::none()` returns the 3xx
+/// verbatim so the caller can reject it.
+///
+/// Returned as a `Result` so the fail-closed invariant is testable — callers
+/// must never substitute a redirect-following client on build failure. Shares
+/// the localhost `resolve`/pool config with the app-wide `http_client`.
+pub fn build_media_fetch_client() -> reqwest::Result<reqwest::Client> {
+    reqwest::Client::builder()
+        .resolve("localhost", std::net::SocketAddr::from(([127, 0, 0, 1], 0)))
+        .pool_idle_timeout(std::time::Duration::from_secs(10))
+        .pool_max_idle_per_host(1)
+        .redirect(reqwest::redirect::Policy::none())
+        .build()
+}
+
 pub fn build_app_state() -> AppState {
     // Env var takes precedence (dev/CI). If absent, resolve_persisted_identity()
     // in setup() will replace the ephemeral placeholder with a persisted key.
@@ -177,6 +207,11 @@ pub fn build_app_state() -> AppState {
             .pool_max_idle_per_host(1)
             .build()
             .unwrap_or_else(|_| reqwest::Client::new()),
+        media_fetch_client: build_media_fetch_client().expect(
+            "media_fetch_client must build with redirect::Policy::none(); a \
+             redirect-following fallback would forward the minted media auth \
+             header across origins (redirect-hop SSRF)",
+        ),
         relay_url_override: Mutex::new(None),
         managed_agent_restore_pending: AtomicBool::new(false),
         managed_agent_profile_reconcile_enabled: AtomicBool::new(true),

desktop/src-tauri/src/commands/workspace.rs

@@ -105,6 +105,7 @@ pub async fn apply_workspace(
     relay_url: String,
     nsec: Option<String>,
     repos_dir: Option<String>,
+    agent_managed_profiles: Option<bool>,
     app: AppHandle,
 ) -> Result<(), String> {
     let restore_app = app.clone();
@@ -151,6 +152,13 @@ pub async fn apply_workspace(
             *keys_guard = keys;
         }
 
+        // Keep the backend-side reconcile guard aligned with the frontend
+        // experiment before workspace activation can spawn any agents. Missing
+        // means the stable behavior: desktop remains authoritative.
+        state
+            .managed_agent_profile_reconcile_enabled
+            .store(!agent_managed_profiles.unwrap_or(false), Ordering::Release);
+
         // ── One-shot legacy migration (non-fatal) ─────────────────────────────
         // Pin any blank-relay agent record to the first workspace applied
         // after boot — exactly what blank would have resolved to at boot