fix(.gitignore): anchor Python build artifacts; recover panel/src/lib (28 files)

The 'lib/' rule (intended for Python virtualenv at repo root) was matching panel/src/lib/, hiding the entire panel API client + utility tree from git. Anchored Python build-artifact rules to the repo root with a leading slash so they only match at the top level. Adds 28 panel/src/lib files that should have been tracked from day one.

panel/src/lib/constants.ts

@@ -0,0 +1,27 @@
+/**
+ * Application Constants
+ * 
+ * Centralized configuration values used across the application.
+ */
+
+// CEO agent credentials for control panel operations
+// In production, this would come from authentication
+export const CEO_AGENT_ID = "00000000-0000-0000-0000-000000000001";
+export const CEO_ROLE = "ceo";
+
+// API URLs - relative URLs go through Next.js proxy (avoids CORS)
+export const API_URL = process.env.NEXT_PUBLIC_API_URL || "/api";
+export const WS_URL = process.env.NEXT_PUBLIC_WS_URL || "/ws";
+
+// Pagination defaults
+export const DEFAULT_PAGE_SIZE = 20;
+export const MAX_PAGE_SIZE = 100;
+
+// WebSocket settings
+export const WS_RECONNECT_INTERVAL = 5000;  // Start at 5s, exponential backoff from there
+export const WS_MAX_RECONNECT_ATTEMPTS = 3; // Give up after 3 attempts
+export const WS_HEARTBEAT_INTERVAL = 30000;
+
+// UI settings
+export const STREAM_MAX_MESSAGES = 100;
+export const NOTIFICATION_MAX_DISPLAY = 10;