Add container-native scheduled task system with timezone support

Introduces a cron-based scheduler that lets Claude set up recurring and
one-time tasks inside containers. Tasks run as separate Claude Code agents
and persist across container recreation via the named volume.

New files:
- container/triple-c-scheduler: CLI for add/remove/enable/disable/list/logs/run/notifications
- container/triple-c-task-runner: cron wrapper with flock, logging, notifications, auto-cleanup

Key changes:
- Dockerfile: add cron package and COPY both scripts
- entrypoint.sh: timezone setup, cron daemon, crontab restore, env saving
- container.rs: init=true for zombie reaping, TZ env, scheduler instructions, timezone recreation check
- image.rs: embed scheduler scripts in build context
- app_settings.rs + types.ts: timezone field
- settings_commands.rs: detect_host_timezone via iana-time-zone crate
- SettingsPanel.tsx: timezone input with auto-detection

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/components/settings/SettingsPanel.tsx

@@ -6,6 +6,7 @@ import { useSettings } from "../../hooks/useSettings";
 import { useUpdates } from "../../hooks/useUpdates";
 import ClaudeInstructionsModal from "../projects/ClaudeInstructionsModal";
 import EnvVarsModal from "../projects/EnvVarsModal";
+import { detectHostTimezone } from "../../lib/tauri-commands";
 import type { EnvVar } from "../../lib/types";
 
 export default function SettingsPanel() {
@@ -14,6 +15,7 @@ export default function SettingsPanel() {
   const [globalInstructions, setGlobalInstructions] = useState(appSettings?.global_claude_instructions ?? "");
   const [globalEnvVars, setGlobalEnvVars] = useState<EnvVar[]>(appSettings?.global_custom_env_vars ?? []);
   const [checkingUpdates, setCheckingUpdates] = useState(false);
+  const [timezone, setTimezone] = useState(appSettings?.timezone ?? "");
   const [showInstructionsModal, setShowInstructionsModal] = useState(false);
   const [showEnvVarsModal, setShowEnvVarsModal] = useState(false);
 
@@ -21,7 +23,18 @@ export default function SettingsPanel() {
   useEffect(() => {
     setGlobalInstructions(appSettings?.global_claude_instructions ?? "");
     setGlobalEnvVars(appSettings?.global_custom_env_vars ?? []);
-  }, [appSettings?.global_claude_instructions, appSettings?.global_custom_env_vars]);
+    setTimezone(appSettings?.timezone ?? "");
+  }, [appSettings?.global_claude_instructions, appSettings?.global_custom_env_vars, appSettings?.timezone]);
+
+  // Auto-detect timezone on first load if not yet set
+  useEffect(() => {
+    if (appSettings && !appSettings.timezone) {
+      detectHostTimezone().then((tz) => {
+        setTimezone(tz);
+        saveSettings({ ...appSettings, timezone: tz });
+      }).catch(() => {});
+    }
+  }, [appSettings?.timezone]);
 
   const handleCheckNow = async () => {
     setCheckingUpdates(true);
@@ -46,6 +59,26 @@ export default function SettingsPanel() {
       <DockerSettings />
       <AwsSettings />
 
+      {/* Container Timezone */}
+      <div>
+        <label className="block text-sm font-medium mb-1">Container Timezone</label>
+        <p className="text-xs text-[var(--text-secondary)] mb-1.5">
+          Timezone for containers — affects scheduled task timing (IANA format, e.g. America/New_York)
+        </p>
+        <input
+          type="text"
+          value={timezone}
+          onChange={(e) => setTimezone(e.target.value)}
+          onBlur={async () => {
+            if (appSettings) {
+              await saveSettings({ ...appSettings, timezone: timezone || null });
+            }
+          }}
+          placeholder="UTC"
+          className="w-full px-2 py-1 text-sm bg-[var(--bg-primary)] border border-[var(--border-color)] rounded focus:outline-none focus:border-[var(--accent)]"
+        />
+      </div>
+
       {/* Global Claude Instructions */}
       <div>
         <label className="block text-sm font-medium mb-1">Claude Instructions</label>

app/src/lib/tauri-commands.ts

@@ -35,6 +35,8 @@ export const detectAwsConfig = () =>
   invoke<string | null>("detect_aws_config");
 export const listAwsProfiles = () =>
   invoke<string[]>("list_aws_profiles");
+export const detectHostTimezone = () =>
+  invoke<string>("detect_host_timezone");
 
 // Terminal
 export const openTerminalSession = (projectId: string, sessionId: string) =>

app/src/lib/types.ts

@@ -98,6 +98,7 @@ export interface AppSettings {
   global_custom_env_vars: EnvVar[];
   auto_check_updates: boolean;
   dismissed_update_version: string | null;
+  timezone: string | null;
 }
 
 export interface UpdateInfo {