[pierre] fix: self-heal half-installed vite warm cache

An npm install killed mid-warm leaves node_modules/ populated but no .bin/, so _ensure_warm_cache (which only checked the dir exists) trusted the half-tree forever and every app symlinked to it died with `vite: command not found`. Gate the cache on .bin/vite existing, and harden the app's frontend/run.sh skip-install guard the same way.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/apps/outputs/view_builder_templates.py

@@ -286,15 +286,27 @@ def _warm_cache_dir() -> str:
     return os.path.join(base, _warm_cache_digest())
 
 
+def _warm_cache_is_complete(cache_modules: str) -> bool:
+    """A populated node_modules/ dir is not proof of a *finished* install.
+    npm links package bins (node_modules/.bin/*) in the final phase, so an
+    install killed partway (e.g. Electron quit mid-warm) leaves the package
+    trees on disk but no .bin/. The old `os.path.isdir(node_modules)` check
+    then trusted that half-tree forever, every app symlinked to it, and
+    `npm run dev` died with `vite: command not found`. Require the one bin
+    every webapp-template app actually launches with so a partial cache is
+    treated as not-ready and repopulated instead of cached as good."""
+    return os.path.exists(os.path.join(cache_modules, ".bin", "vite"))
+
+
 def _ensure_warm_cache() -> str | None:
-    """Populate the warm-cache node_modules if missing. Returns the
-    absolute path to the populated `node_modules` directory, or None on
-    failure. Thread-safe; concurrent callers block on a single install
-    instead of racing. Idempotent and fast after the first call."""
+    """Populate the warm-cache node_modules if missing or incomplete.
+    Returns the absolute path to the populated `node_modules` directory, or
+    None on failure. Thread-safe; concurrent callers block on a single
+    install instead of racing. Idempotent and fast after the first call."""
     cache_dir = _warm_cache_dir()
     cache_modules = os.path.join(cache_dir, "node_modules")
 
-    if os.path.isdir(cache_modules):
+    if _warm_cache_is_complete(cache_modules):
         return cache_modules
 
     # Prefer a pre-extracted bundled tree: junction the workspace straight at it,
@@ -305,7 +317,7 @@ def _ensure_warm_cache() -> str | None:
         return bundled
 
     with _warm_cache_lock:
-        if os.path.isdir(cache_modules):
+        if _warm_cache_is_complete(cache_modules):
             return cache_modules
         # Fast path: pre-built archive shipped inside the release. The
         # build script generates this so users hitting OpenSwarm for the

backend/apps/outputs/webapp_template/frontend/run.sh

@@ -43,8 +43,13 @@ fi
 # to vite. Only run npm install when node_modules is genuinely missing
 # or empty — e.g. a workspace seeded before the warm-cache existed, or
 # the user's cache was cleared.
-if [ -d node_modules ] && [ -n "$(ls -A node_modules 2>/dev/null)" ]; then
-    echo "Dependencies already present — skipping install."
+# A non-empty node_modules is NOT proof of a finished install. 
+# non-empty -> skip" check then trusted that, and `npm run dev` died with
+# `vite: command not found`. Gate on the bin we actually launch with so a
+# broken/partial tree self-heals via install instead of being skipped.
+#So thats why i  explicitly have "/.bin/vite"
+if [ -e node_modules/.bin/vite ]; then
+    echo "Dependencies already present - skipping install."
 else
     echo "Installing dependencies..."
     "$NPM" install --prefer-offline --no-audit --no-fund