fix(starlark): critical bug fixes and code quality improvements

Critical fixes:
- Fix stack overflow in safeLocalStorage (was recursively calling itself)
- Fix duplicate event listeners on Starlark grid (added sentinel check)
- Fix JSON validation to fail fast on malformed data instead of silently passing

Error handling improvements:
- Narrow exception catches to specific types (OSError, json.JSONDecodeError, ValueError)
- Use logger.exception() with exc_info=True for better stack traces
- Replace generic "except Exception" with specific exception types

Logging improvements:
- Add "[Starlark Pixlet]" context tags to pixlet_renderer logs
- Redact sensitive config values from debug logs (API keys, etc.)
- Add file_path context to schema parsing warnings

Documentation:
- Fix markdown lint issues (add language tags to code blocks)
- Fix time unit spacing: "(5min)" -> "(5 min)"

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docs/STARLARK_APPS_GUIDE.md

@@ -27,7 +27,7 @@ The Starlark Apps plugin for LEDMatrix enables you to run **Tidbyt/Tronbyte comm
 
 ### Architecture
 
-```
+```text
 ┌─────────────────────────────────────────────────────────┐
 │                    LEDMatrix System                      │
 │  ┌────────────────────────────────────────────────────┐ │
@@ -199,7 +199,7 @@ Tronbyte/Tidbyt apps are designed for **64×32 displays**. LEDMatrix automatical
 
 The plugin calculates optimal magnification based on your display:
 
-```
+```text
 magnify = floor(min(display_width / 64, display_height / 32))
 ```
 
@@ -250,7 +250,7 @@ Apps without extracted schemas can still run with default settings.
 
 ## File Structure
 
-```
+```text
 LEDMatrix/
 ├── plugin-repos/starlark-apps/     # Plugin source code
 │   ├── manager.py                  # Main plugin logic
@@ -378,7 +378,7 @@ Cached WebP files are stored in `starlark-apps/{app-id}/cached_render.webp`
 
 Balance number of enabled apps with display duration:
 - 5 apps × 15s = 75s full cycle
-- 20 apps × 15s = 300s (5min) cycle
+- 20 apps × 15s = 300s (5 min) cycle
 
 Long cycles may cause apps to render before being displayed.
 

plugin-repos/starlark-apps/manager.py

@@ -63,7 +63,7 @@ class StarlarkApp:
             try:
                 with open(self.config_file, 'r') as f:
                     return json.load(f)
-            except Exception as e:
+            except (OSError, json.JSONDecodeError) as e:
                 logger.warning(f"Could not load config for {self.app_id}: {e}")
         return {}
 
@@ -73,7 +73,7 @@ class StarlarkApp:
             try:
                 with open(self.schema_file, 'r') as f:
                     return json.load(f)
-            except Exception as e:
+            except (OSError, json.JSONDecodeError) as e:
                 logger.warning(f"Could not load schema for {self.app_id}: {e}")
         return None
 
@@ -118,6 +118,11 @@ class StarlarkApp:
             if isinstance(value, str) and value.strip().startswith('{'):
                 try:
                     loc = json.loads(value)
+                except json.JSONDecodeError as e:
+                    return f"Invalid JSON for key {key}: {e}"
+
+                # Validate lat/lng if present
+                try:
                     if 'lat' in loc:
                         lat = float(loc['lat'])
                         if not -90 <= lat <= 90:
@@ -126,9 +131,8 @@ class StarlarkApp:
                         lng = float(loc['lng'])
                         if not -180 <= lng <= 180:
                             return f"Longitude {lng} out of range [-180, 180] for key {key}"
-                except (json.JSONDecodeError, ValueError, KeyError) as e:
+                except ValueError as e:
-                    # Not a location field, that's fine
+                    return f"Invalid numeric value for {key}: {e}"
-                    pass
 
         return None
 
@@ -584,8 +588,8 @@ class StarlarkAppsPlugin(BasePlugin):
                 fcntl.flock(lock_fd, fcntl.LOCK_UN)
                 os.close(lock_fd)
 
-        except Exception as e:
+        except (OSError, IOError, json.JSONDecodeError, ValueError) as e:
-            self.logger.error(f"Error saving manifest: {e}")
+            self.logger.exception("Error saving manifest while writing manifest file", exc_info=True)
             # Clean up temp file if it exists
             if temp_file is not None and temp_file.exists():
                 try:
@@ -651,8 +655,8 @@ class StarlarkAppsPlugin(BasePlugin):
                 fcntl.flock(lock_fd, fcntl.LOCK_UN)
                 os.close(lock_fd)
 
-        except Exception as e:
+        except (OSError, IOError, json.JSONDecodeError, ValueError) as e:
-            self.logger.error(f"Error updating manifest: {e}")
+            self.logger.exception("Error updating manifest during read-modify-write cycle", exc_info=True)
             # Clean up temp file if it exists
             if temp_file is not None and temp_file.exists():
                 try:

plugin-repos/starlark-apps/pixlet_renderer.py

@@ -41,9 +41,9 @@ class PixletRenderer:
         self.pixlet_binary = self._find_pixlet_binary(pixlet_path)
 
         if self.pixlet_binary:
-            logger.info(f"Pixlet renderer initialized with binary: {self.pixlet_binary}")
+            logger.info(f"[Starlark Pixlet] Pixlet renderer initialized with binary: {self.pixlet_binary}")
         else:
-            logger.warning("Pixlet binary not found - rendering will fail")
+            logger.warning("[Starlark Pixlet] Pixlet binary not found - rendering will fail")
 
     def _find_pixlet_binary(self, explicit_path: Optional[str] = None) -> Optional[str]:
         """
@@ -280,7 +280,13 @@ class PixletRenderer:
                 "-m", str(magnify)
             ])
 
-            logger.debug(f"Executing Pixlet: {' '.join(cmd)}")
+            # Build sanitized command for logging (redact sensitive values)
+            sanitized_cmd = [self.pixlet_binary, "render", star_file]
+            if config:
+                config_keys = list(config.keys())
+                sanitized_cmd.append(f"[{len(config_keys)} config entries: {', '.join(config_keys)}]")
+            sanitized_cmd.extend(["-o", output_path, "-m", str(magnify)])
+            logger.debug(f"Executing Pixlet: {' '.join(sanitized_cmd)}")
 
             # Execute rendering
             safe_cwd = self._get_safe_working_directory(star_file)
@@ -373,6 +379,7 @@ class PixletRenderer:
         # Extract get_schema() function body
         schema_body = self._extract_get_schema_body(content)
         if not schema_body:
+            logger.debug(f"No get_schema() function found in {file_path}")
             return None
 
         # Extract version
@@ -397,6 +404,7 @@ class PixletRenderer:
 
         if bracket_count != 0:
             # Unmatched brackets
+            logger.warning(f"Unmatched brackets in schema fields for {file_path}")
             return {"version": version, "schema": []}
 
         fields_text = schema_body[fields_start_match.end():i-1]

web_interface/static/v3/plugins_manager.js

@@ -4,7 +4,7 @@ const safeLocalStorage = {
     getItem(key) {
         try {
             if (typeof localStorage !== 'undefined') {
-                return safeLocalStorage.getItem(key);
+                return localStorage.getItem(key);
             }
         } catch (e) {
             console.warn(`safeLocalStorage.getItem failed for key "${key}":`, e.message);
@@ -14,7 +14,7 @@ const safeLocalStorage = {
     setItem(key, value) {
         try {
             if (typeof localStorage !== 'undefined') {
-                safeLocalStorage.setItem(key, value);
+                localStorage.setItem(key, value);
                 return true;
             }
         } catch (e) {
@@ -7924,24 +7924,27 @@ setTimeout(function() {
             </div>`;
         }).join('');
 
-        // Add delegated event listeners for install and view buttons
+        // Add delegated event listener only once (prevent duplicate handlers)
-        grid.addEventListener('click', function(e) {
+        if (!grid.dataset.starlarkHandlerAttached) {
-            const button = e.target.closest('button[data-action]');
+            grid.addEventListener('click', function handleStarlarkGridClick(e) {
-            if (!button) return;
+                const button = e.target.closest('button[data-action]');
+                if (!button) return;
 
-            const card = button.closest('.plugin-card');
+                const card = button.closest('.plugin-card');
-            if (!card) return;
+                if (!card) return;
 
-            const appId = card.dataset.appId;
+                const appId = card.dataset.appId;
-            if (!appId) return;
+                if (!appId) return;
 
-            const action = button.dataset.action;
+                const action = button.dataset.action;
-            if (action === 'install') {
+                if (action === 'install') {
-                window.installStarlarkApp(appId);
+                    window.installStarlarkApp(appId);
-            } else if (action === 'view') {
+                } else if (action === 'view') {
-                window.open('https://github.com/tronbyt/apps/tree/main/apps/' + encodeURIComponent(appId), '_blank');
+                    window.open('https://github.com/tronbyt/apps/tree/main/apps/' + encodeURIComponent(appId), '_blank');
-            }
+                }
-        });
+            });
+            grid.dataset.starlarkHandlerAttached = 'true';
+        }
     }
 
     // ── Filter UI Updates ───────────────────────────────────────────────────