feat: enable Remote Control (BRIDGE_MODE) with stub completions

- Add BRIDGE_MODE to DEFAULT_FEATURES in dev.ts
- Implement peerSessions.ts: cross-session messaging via bridge API
- Implement webhookSanitizer.ts: redact secrets from webhook payloads
- Replace any stubs in controlTypes.ts with Zod schema-inferred types
- Fix tengu_bridge_system_init default to true for app "active" status

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/bridge/webhookSanitizer.ts

@@ -1,3 +1,57 @@
-// Auto-generated stub — replace with real implementation
-export {};
-export const sanitizeInboundWebhookContent: (content: string) => string = (content) => content;
+/**
+ * Sanitize inbound GitHub webhook payload content before it enters the session.
+ *
+ * Called from useReplBridge.tsx when feature('KAIROS_GITHUB_WEBHOOKS') is enabled.
+ * Strips known secret patterns (tokens, API keys, credentials) while preserving
+ * the meaningful content (PR titles, descriptions, commit messages, etc.).
+ *
+ * Must be synchronous and never throw — on error, returns the original content.
+ */
+
+/** Patterns that match known secret/token formats. */
+const SECRET_PATTERNS: Array<{ pattern: RegExp; replacement: string }> = [
+  // GitHub tokens (PAT, OAuth, App, Server-to-server)
+  { pattern: /\b(ghp|gho|ghs|ghu|github_pat)_[A-Za-z0-9_]{10,}\b/g, replacement: '[REDACTED_GITHUB_TOKEN]' },
+  // Anthropic API keys
+  { pattern: /\bsk-ant-[A-Za-z0-9_-]{10,}\b/g, replacement: '[REDACTED_ANTHROPIC_KEY]' },
+  // Generic Bearer tokens in headers
+  { pattern: /(Bearer\s+)[A-Za-z0-9._\-/+=]{20,}/gi, replacement: '$1[REDACTED_TOKEN]' },
+  // AWS access keys
+  { pattern: /\b(AKIA|ASIA)[A-Z0-9]{16}\b/g, replacement: '[REDACTED_AWS_KEY]' },
+  // AWS secret keys (40-char base64-like strings after common labels)
+  { pattern: /(aws_secret_access_key|secret_key|SecretAccessKey)['":\s=]+[A-Za-z0-9/+=]{30,}/gi, replacement: '$1=[REDACTED_AWS_SECRET]' },
+  // Generic API key patterns (key=value or "key": "value")
+  { pattern: /(api[_-]?key|apikey|secret|password|token|credential)['":\s=]+["']?[A-Za-z0-9._\-/+=]{16,}["']?/gi, replacement: '$1=[REDACTED]' },
+  // npm tokens
+  { pattern: /\bnpm_[A-Za-z0-9]{36}\b/g, replacement: '[REDACTED_NPM_TOKEN]' },
+  // Slack tokens
+  { pattern: /\bxox[bporas]-[A-Za-z0-9-]{10,}\b/g, replacement: '[REDACTED_SLACK_TOKEN]' },
+]
+
+/** Maximum content length before truncation (100KB). */
+const MAX_CONTENT_LENGTH = 100_000
+
+export function sanitizeInboundWebhookContent(content: string): string {
+  try {
+    if (!content) return content
+
+    let sanitized = content
+
+    // Truncate excessively large payloads
+    if (sanitized.length > MAX_CONTENT_LENGTH) {
+      sanitized = sanitized.slice(0, MAX_CONTENT_LENGTH) + '\n... [truncated]'
+    }
+
+    // Redact known secret patterns
+    for (const { pattern, replacement } of SECRET_PATTERNS) {
+      // Reset lastIndex for global regexes
+      pattern.lastIndex = 0
+      sanitized = sanitized.replace(pattern, replacement)
+    }
+
+    return sanitized
+  } catch {
+    // Never throw — return original content on any error
+    return content
+  }
+}