fix(targets): DRY signal handling, remove redundant guards, harden config manager

- Extract signal forwarding to reusable src/utils/signal-forwarder.ts
- Update shell-executor, claude-adapter, droid-adapter to use shared utility
- Remove 35 lines of redundant duplicate guards in src/ccs.ts
- Harden droid-config-manager with lock constants and race-safe ensureFactoryDir
- Update help-command with --target usage examples
- Update maintainability metrics baseline

docs/metrics/maintainability-baseline.json

@@ -2,8 +2,8 @@
   "sourceDirectory": "src",
   "largeFileThresholdLoc": 350,
   "typeScriptFileCount": 355,
-  "locInSrc": 71420,
+  "locInSrc": 71353,
-  "processExitReferenceCount": 188,
+  "processExitReferenceCount": 185,
-  "synchronousFsApiReferenceCount": 880,
+  "synchronousFsApiReferenceCount": 879,
   "largeFileCountOver350Loc": 56
 }

src/ccs.ts

@@ -725,7 +725,7 @@ async function main(): Promise<void> {
 
     // For non-claude targets, verify target binary exists once and pass it through.
     const targetBinaryInfo = targetAdapter?.detectBinary() ?? null;
-    if (resolvedTarget !== 'claude' && (!targetAdapter || !targetBinaryInfo)) {
+    if (resolvedTarget !== 'claude' && !targetBinaryInfo) {
       const displayName = targetAdapter?.displayName || resolvedTarget;
       console.error(fail(`${displayName} CLI not found.`));
       if (resolvedTarget === 'droid') {
@@ -759,17 +759,6 @@ async function main(): Promise<void> {
     }
 
     if (profileInfo.type === 'cliproxy') {
-      // Guard: non-claude targets don't support CLIProxy flow yet
-      if (resolvedTarget !== 'claude') {
-        if (!targetAdapter?.supportsProfileType('cliproxy')) {
-          console.error(
-            fail(`${targetAdapter?.displayName || 'Target'} does not support CLIProxy profiles`)
-          );
-          console.error(info('Use a settings-based profile with --target instead'));
-          process.exit(1);
-        }
-      }
-
       // CLIPROXY FLOW: OAuth-based profiles (gemini, codex, agy, qwen) or user-defined variants
       // Inject WebSearch hook into profile settings before launch
       ensureProfileHooks(profileInfo.name);
@@ -788,16 +777,6 @@ async function main(): Promise<void> {
         profileName: profileInfo.name,
       });
     } else if (profileInfo.type === 'copilot') {
-      // Guard: non-claude targets don't support Copilot flow
-      if (resolvedTarget !== 'claude') {
-        if (!targetAdapter?.supportsProfileType('copilot')) {
-          console.error(
-            fail(`${targetAdapter?.displayName || 'Target'} does not support Copilot profiles`)
-          );
-          process.exit(1);
-        }
-      }
-
       // COPILOT FLOW: GitHub Copilot subscription via copilot-api proxy
       // Inject WebSearch hook into profile settings before launch
       ensureProfileHooks(profileInfo.name);
@@ -943,19 +922,6 @@ async function main(): Promise<void> {
         execClaude(claudeCli, ['--settings', expandedSettingsPath, ...remainingArgs], envVars);
       }
     } else if (profileInfo.type === 'account') {
-      // Guard: non-claude targets don't support account profiles
-      if (resolvedTarget !== 'claude') {
-        if (!targetAdapter?.supportsProfileType('account')) {
-          console.error(
-            fail(
-              `${targetAdapter?.displayName || 'Target'} does not support account-based profiles`
-            )
-          );
-          console.error(info('Use a settings-based profile with --target instead'));
-          process.exit(1);
-        }
-      }
-
       // NEW FLOW: Account-based profile (work, personal)
       // All platforms: Use instance isolation with CLAUDE_CONFIG_DIR
       const registry = new ProfileRegistry();

src/commands/help-command.ts

@@ -312,6 +312,13 @@ Run ${color('ccs config', 'command')} for web dashboard`.trim();
     ['ccsd <profile> [args]', 'Shorthand for: ccs <profile> --target droid'],
   ]);
 
+  // Multi-target examples
+  printSubSection('Multi-Target', [
+    ['ccs glm --target droid', 'Run GLM profile on Droid CLI'],
+    ['ccsd glm', 'Same as above (alias)'],
+    ['ccs glm', 'Run GLM profile on Claude Code (default)'],
+  ]);
+
   // Configuration
   printConfigSection('Configuration', [
     ['Config File:', isUnifiedMode() ? `${dirDisplay}/config.yaml` : `${dirDisplay}/config.json`],

src/targets/claude-adapter.ts

@@ -11,6 +11,7 @@ import { detectClaudeCli, getClaudeCliInfo } from '../utils/claude-detector';
 import { escapeShellArg, stripAnthropicEnv } from '../utils/shell-executor';
 import { ErrorManager } from '../utils/error-manager';
 import { getWebSearchHookEnv } from '../utils/websearch-manager';
+import { forwardSignals } from '../utils/signal-forwarder';
 
 export class ClaudeAdapter implements TargetAdapter {
   readonly type: TargetType = 'claude';
@@ -99,24 +100,7 @@ export class ClaudeAdapter implements TargetAdapter {
       });
     }
 
-    const forwardSigInt = () => {
+    const cleanupSignalHandlers = forwardSignals(child);
-      if (!child.killed) child.kill('SIGINT');
-    };
-    const forwardSigTerm = () => {
-      if (!child.killed) child.kill('SIGTERM');
-    };
-    const forwardSighup = () => {
-      if (!child.killed) child.kill('SIGHUP');
-    };
-    process.on('SIGINT', forwardSigInt);
-    process.on('SIGTERM', forwardSigTerm);
-    process.on('SIGHUP', forwardSighup);
-
-    const cleanupSignalHandlers = () => {
-      process.removeListener('SIGINT', forwardSigInt);
-      process.removeListener('SIGTERM', forwardSigTerm);
-      process.removeListener('SIGHUP', forwardSighup);
-    };
 
     child.on('exit', (code, signal) => {
       cleanupSignalHandlers();

src/targets/droid-adapter.ts

@@ -11,6 +11,7 @@ import { TargetAdapter, TargetBinaryInfo, TargetCredentials, TargetType } from '
 import { getDroidBinaryInfo, detectDroidCli, checkDroidVersion } from './droid-detector';
 import { upsertCcsModel } from './droid-config-manager';
 import { escapeShellArg } from '../utils/shell-executor';
+import { forwardSignals } from '../utils/signal-forwarder';
 
 export class DroidAdapter implements TargetAdapter {
   readonly type: TargetType = 'droid';
@@ -118,24 +119,7 @@ export class DroidAdapter implements TargetAdapter {
       });
     }
 
-    const forwardSigInt = () => {
+    const cleanupSignalHandlers = forwardSignals(child);
-      if (!child.killed) child.kill('SIGINT');
-    };
-    const forwardSigTerm = () => {
-      if (!child.killed) child.kill('SIGTERM');
-    };
-    const forwardSighup = () => {
-      if (!child.killed) child.kill('SIGHUP');
-    };
-    process.on('SIGINT', forwardSigInt);
-    process.on('SIGTERM', forwardSigTerm);
-    process.on('SIGHUP', forwardSighup);
-
-    const cleanupSignalHandlers = () => {
-      process.removeListener('SIGINT', forwardSigInt);
-      process.removeListener('SIGTERM', forwardSigTerm);
-      process.removeListener('SIGHUP', forwardSighup);
-    };
 
     child.on('exit', (code, signal) => {
       cleanupSignalHandlers();

src/targets/droid-config-manager.ts

@@ -12,6 +12,11 @@ import * as lockfile from 'proper-lockfile';
 
 const CCS_MODEL_PREFIX = 'ccs-';
 
+/** Lock configuration for concurrent write safety */
+const LOCK_STALE_MS = 10000;
+const LOCK_RETRY_MIN_MS = 200;
+const LOCK_RETRY_MAX_MS = 1000;
+
 /**
  * Validate profile name to prevent filesystem/security issues.
  * Only alphanumeric, underscore, hyphen allowed.
@@ -104,8 +109,11 @@ function getSettingsPath(): string {
  */
 function ensureFactoryDir(): void {
   const dir = getFactoryDir();
-  if (!fs.existsSync(dir)) {
+  try {
     fs.mkdirSync(dir, { recursive: true, mode: 0o700 });
+  } catch (err) {
+    const error = err as NodeJS.ErrnoException;
+    if (error.code !== 'EEXIST') throw error;
   }
 }
 
@@ -181,8 +189,8 @@ async function acquireFactoryLock(retries: number): Promise<() => Promise<void>>
   const factoryDir = getFactoryDir();
   try {
     return await lockfile.lock(factoryDir, {
-      stale: 10000,
+      stale: LOCK_STALE_MS,
-      retries: { retries, minTimeout: 200, maxTimeout: 1000 },
+      retries: { retries, minTimeout: LOCK_RETRY_MIN_MS, maxTimeout: LOCK_RETRY_MAX_MS },
     });
   } catch (error) {
     throw new Error(

src/utils/shell-executor.ts

@@ -7,6 +7,7 @@
 import { spawn, spawnSync, ChildProcess } from 'child_process';
 import { ErrorManager } from './error-manager';
 import { getWebSearchHookEnv } from './websearch-manager';
+import { forwardSignals } from './signal-forwarder';
 
 /**
  * Strip ANTHROPIC_* env vars from an environment object.
@@ -127,24 +128,7 @@ export function execClaude(
     });
   }
 
-  const forwardSigInt = () => {
+  const cleanupSignalHandlers = forwardSignals(child);
-    if (!child.killed) child.kill('SIGINT');
-  };
-  const forwardSigTerm = () => {
-    if (!child.killed) child.kill('SIGTERM');
-  };
-  const forwardSighup = () => {
-    if (!child.killed) child.kill('SIGHUP');
-  };
-  process.on('SIGINT', forwardSigInt);
-  process.on('SIGTERM', forwardSigTerm);
-  process.on('SIGHUP', forwardSighup);
-
-  const cleanupSignalHandlers = () => {
-    process.removeListener('SIGINT', forwardSigInt);
-    process.removeListener('SIGTERM', forwardSigTerm);
-    process.removeListener('SIGHUP', forwardSighup);
-  };
 
   child.on('exit', (code, signal) => {
     cleanupSignalHandlers();

src/utils/signal-forwarder.ts

@@ -0,0 +1,33 @@
+/**
+ * Signal Forwarder
+ *
+ * Shared utility for forwarding process signals to child processes
+ * and cleaning up handlers on exit.
+ */
+import { ChildProcess } from 'child_process';
+
+/**
+ * Forward SIGINT, SIGTERM, SIGHUP to a child process.
+ * Returns a cleanup function to remove the handlers.
+ */
+export function forwardSignals(child: ChildProcess): () => void {
+  const forwardSigInt = () => {
+    if (!child.killed) child.kill('SIGINT');
+  };
+  const forwardSigTerm = () => {
+    if (!child.killed) child.kill('SIGTERM');
+  };
+  const forwardSighup = () => {
+    if (!child.killed) child.kill('SIGHUP');
+  };
+
+  process.on('SIGINT', forwardSigInt);
+  process.on('SIGTERM', forwardSigTerm);
+  process.on('SIGHUP', forwardSighup);
+
+  return () => {
+    process.removeListener('SIGINT', forwardSigInt);
+    process.removeListener('SIGTERM', forwardSigTerm);
+    process.removeListener('SIGHUP', forwardSighup);
+  };
+}