perf: demand-load mobile workspace features (Closes #1468)

src/frontend_bundle.py

@@ -140,7 +140,16 @@ def build_frontend(frontend_dir: Path) -> FrontendBuild:
     for source in sources:
         if source != WORKER_RUNTIME_SOURCE:
             worker = worker.replace(f"  BASE + '{source}',\n", "")
-    optional_features = feature_bundles
+    # The workspace hydrator fetches these large chunks only when a route or action
+    # needs them; warming them here would defeat demand loading on every visit.
+    optional_features = {
+        name: bundle for name, bundle in feature_bundles.items()
+        if name not in {"today-timer", "planning"}
+    }
+    demand_features = {
+        name: bundle for name, bundle in feature_bundles.items()
+        if name in {"today-timer", "planning"}
+    }
     worker = worker.replace(
         "  BASE + 'static/dashboard.css',\n",
         "  BASE + 'static/dashboard.css',\n"
@@ -151,6 +160,11 @@ def build_frontend(frontend_dir: Path) -> FrontendBuild:
         "const OPTIONAL_FEATURES = [\n"
         + "".join(f"  BASE + '{bundle.runtime_name}',\n" for bundle in optional_features.values()),
     )
+    worker = worker.replace(
+        "const DEMAND_FEATURES = [\n",
+        "const DEMAND_FEATURES = [\n"
+        + "".join(f"  BASE + '{bundle.runtime_name}',\n" for bundle in demand_features.values()),
+    )
     worker = CACHE_DECLARATION.sub(
         "const CACHE = 'stackchain-dashboard-shell-BUILD';", worker, count=1
     )