diff --git a/src/ccs.ts b/src/ccs.ts
index 99c57ca3..e858ab1d 100644
--- a/src/ccs.ts
+++ b/src/ccs.ts
@@ -30,7 +30,7 @@ import { getGlobalEnvConfig } from './config/unified-config-loader';
 import { ensureProfileHooks as ensureImageAnalyzerHooks } from './utils/hooks/image-analyzer-profile-hook-injector';
 import { getImageAnalysisHookEnv } from './utils/hooks';
 import { fail, info, warn } from './utils/ui';
-import { COPILOT_SUBCOMMAND_TOKENS } from './copilot/constants';
+import { isCopilotSubcommandToken, isLikelyCopilotFlagAlias } from './copilot/constants';
 
 // Import centralized error handling
 import { handleError, runCleanup } from './errors';
@@ -573,12 +573,19 @@ async function main(): Promise<void> {
   }
 
   // Special case: copilot command (GitHub Copilot integration)
-  // Only route to command handler for known subcommands, otherwise treat as profile
-  if (firstArg === 'copilot' && args.length > 1 && COPILOT_SUBCOMMAND_TOKENS.includes(args[1])) {
-    // `ccs copilot <subcommand>` - route to copilot command handler
-    const { handleCopilotCommand } = await import('./commands/copilot-command');
-    const exitCode = await handleCopilotCommand(args.slice(1));
-    process.exit(exitCode);
+  // Route known subcommands and likely mistyped aliases (`--statu`) to command handler.
+  // Non-command Claude args still pass through profile flow.
+  if (firstArg === 'copilot' && args.length > 1) {
+    const copilotToken = args[1];
+    const shouldRouteToCopilotCommand =
+      isCopilotSubcommandToken(copilotToken) ||
+      (args.length === 2 && isLikelyCopilotFlagAlias(copilotToken));
+
+    if (shouldRouteToCopilotCommand) {
+      const { handleCopilotCommand } = await import('./commands/copilot-command');
+      const exitCode = await handleCopilotCommand(args.slice(1));
+      process.exit(exitCode);
+    }
   }
 
   // First-time install: offer setup wizard for interactive users
@@ -955,7 +962,8 @@ async function main(): Promise<void> {
       const exitCode = await executeCopilotProfile(
         copilotConfig,
         remainingArgs,
-        continuityInheritance.claudeConfigDir
+        continuityInheritance.claudeConfigDir,
+        claudeCli
       );
       process.exit(exitCode);
     } else if (profileInfo.type === 'settings') {
diff --git a/src/commands/copilot-command.ts b/src/commands/copilot-command.ts
index 960a7328..2bdb2b1d 100644
--- a/src/commands/copilot-command.ts
+++ b/src/commands/copilot-command.ts
@@ -107,7 +107,8 @@ async function handleAuth(): Promise<number> {
     console.log('');
     console.log('Next steps:');
     console.log('  1. Enable copilot: ccs copilot enable');
-    console.log('  2. Start daemon:   npx copilot-api start');
+    console.log('  2. Start daemon:   ccs copilot start');
+    console.log('     (fallback:      npx copilot-api start)');
     console.log('  3. Use copilot:    ccs copilot');
     return 0;
   } else {
diff --git a/src/copilot/constants.ts b/src/copilot/constants.ts
index c4c0b42f..cc594afd 100644
--- a/src/copilot/constants.ts
+++ b/src/copilot/constants.ts
@@ -41,3 +41,27 @@ export function normalizeCopilotSubcommand(token?: string): string | undefined {
   const alias = COPILOT_FLAG_ALIASES[token as keyof typeof COPILOT_FLAG_ALIASES];
   return alias || token;
 }
+
+export function isCopilotSubcommandToken(token?: string): boolean {
+  return Boolean(token) && COPILOT_SUBCOMMAND_TOKENS.includes(token as string);
+}
+
+/**
+ * Detect likely mistyped copilot flag aliases (e.g. `--statu`).
+ * This helps entrypoint routing show command help instead of falling through
+ * to profile execution for obvious copilot-command typos.
+ */
+export function isLikelyCopilotFlagAlias(token?: string): boolean {
+  if (!token || !token.startsWith('--') || token === '--') {
+    return false;
+  }
+
+  const alias = token.slice(2).toLowerCase();
+  if (!/^[a-z][a-z0-9-]*$/.test(alias)) {
+    return false;
+  }
+
+  return COPILOT_SUBCOMMANDS.some(
+    (subcommand) => subcommand.startsWith(alias) || alias.startsWith(subcommand)
+  );
+}
diff --git a/src/copilot/copilot-daemon.ts b/src/copilot/copilot-daemon.ts
index 29116722..c8cc09fe 100644
--- a/src/copilot/copilot-daemon.ts
+++ b/src/copilot/copilot-daemon.ts
@@ -10,11 +10,28 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as http from 'http';
 import { CopilotDaemonStatus } from './types';
-import { CopilotConfig } from '../config/unified-config-types';
+import { CopilotConfig, DEFAULT_COPILOT_CONFIG } from '../config/unified-config-types';
+import { loadOrCreateUnifiedConfig } from '../config/unified-config-loader';
 import { getCopilotDir, getCopilotApiBinPath } from './copilot-package-manager';
 import { verifyProcessOwnership } from '../cursor/daemon-process-ownership';
 
 const DAEMON_HEALTH_MARKER = 'server running';
+const MIN_PORT = 1;
+const MAX_PORT = 65535;
+
+function isValidPort(port: number): boolean {
+  return Number.isInteger(port) && port >= MIN_PORT && port <= MAX_PORT;
+}
+
+function getConfiguredCopilotPort(): number {
+  try {
+    const config = loadOrCreateUnifiedConfig();
+    const port = config.copilot?.port ?? DEFAULT_COPILOT_CONFIG.port;
+    return isValidPort(port) ? port : DEFAULT_COPILOT_CONFIG.port;
+  } catch {
+    return DEFAULT_COPILOT_CONFIG.port;
+  }
+}
 
 function getPidFilePath(): string {
   return path.join(getCopilotDir(), 'daemon.pid');
@@ -25,6 +42,10 @@ function getPidFilePath(): string {
  * Uses 127.0.0.1 instead of localhost for more reliable local connections.
  */
 export async function isDaemonRunning(port: number): Promise<boolean> {
+  if (!isValidPort(port)) {
+    return false;
+  }
+
   return new Promise((resolve) => {
     const req = http.request(
       {
@@ -136,6 +157,13 @@ function removePidFile(): void {
 export async function startDaemon(
   config: CopilotConfig
 ): Promise<{ success: boolean; pid?: number; error?: string }> {
+  if (!isValidPort(config.port)) {
+    return {
+      success: false,
+      error: `Invalid Copilot daemon port ${config.port}. Expected integer between ${MIN_PORT} and ${MAX_PORT}.`,
+    };
+  }
+
   // Check if already running
   if (await isDaemonRunning(config.port)) {
     return { success: true, pid: getPidFromFile() ?? undefined };
@@ -250,6 +278,7 @@ export async function startDaemon(
  */
 export async function stopDaemon(): Promise<{ success: boolean; error?: string }> {
   const pid = getPidFromFile();
+  const configuredPort = getConfiguredCopilotPort();
 
   if (!pid) {
     // No PID file, try to find by port
@@ -260,8 +289,12 @@ export async function stopDaemon(): Promise<{ success: boolean; error?: string }
   try {
     const ownership = verifyProcessOwnership(pid, (commandLine) => {
       const lower = commandLine.toLowerCase();
+      const hasCopilotApiBinary = /(^|[\\/\s])copilot-api(\.cmd|\.exe)?(\s|$)/.test(lower);
+      const hasStartCommand = /\bstart\b/.test(lower);
+      const hasExpectedPort =
+        lower.includes(`--port ${configuredPort}`) || lower.includes(`--port=${configuredPort}`);
       // copilot-api is launched as `... copilot-api start --port <n>`
-      return lower.includes('copilot-api') && lower.includes(' start');
+      return hasCopilotApiBinary && hasStartCommand && hasExpectedPort;
     });
     if (ownership === 'not-running') {
       removePidFile();
@@ -270,11 +303,23 @@ export async function stopDaemon(): Promise<{ success: boolean; error?: string }
 
     if (ownership === 'not-owned') {
       // PID was reused by an unrelated process.
+      // If daemon is still live on configured port, report failure (stop not completed).
+      if (await isDaemonRunning(configuredPort)) {
+        return {
+          success: false,
+          error: `Refusing to clear PID ${pid}: unrelated process owns PID and daemon is still responding on port ${configuredPort}`,
+        };
+      }
       removePidFile();
       return { success: true };
     }
 
     if (ownership === 'unknown') {
+      // If daemon is not reachable, allow stale PID cleanup.
+      if (!(await isDaemonRunning(configuredPort))) {
+        removePidFile();
+        return { success: true };
+      }
       return {
         success: false,
         error: `Refusing to stop PID ${pid}: unable to verify daemon ownership`,
diff --git a/src/copilot/copilot-executor.ts b/src/copilot/copilot-executor.ts
index 8bfa3ea5..7225b5ed 100644
--- a/src/copilot/copilot-executor.ts
+++ b/src/copilot/copilot-executor.ts
@@ -76,7 +76,8 @@ export function generateCopilotEnv(
 export async function executeCopilotProfile(
   config: CopilotConfig,
   claudeArgs: string[],
-  claudeConfigDir?: string
+  claudeConfigDir?: string,
+  claudeCliPath: string = 'claude'
 ): Promise<number> {
   // Ensure copilot-api is installed (auto-install if missing, auto-update if outdated)
   try {
@@ -125,7 +126,9 @@ export async function executeCopilotProfile(
     } else {
       console.error(fail('copilot-api daemon is not running.'));
       console.error('');
-      console.error('Start the daemon manually:');
+      console.error('Start the daemon:');
+      console.error('  ccs copilot start');
+      console.error('Fallback manual command:');
       console.error(`  npx copilot-api start --port ${config.port}`);
       console.error('');
       console.error('Or enable auto_start in config:');
@@ -158,7 +161,7 @@ export async function executeCopilotProfile(
 
   // Spawn Claude CLI
   return new Promise((resolve) => {
-    const proc = spawn('claude', claudeArgs, {
+    const proc = spawn(claudeCliPath, claudeArgs, {
       stdio: 'inherit',
       env,
       shell: process.platform === 'win32',
diff --git a/src/web-server/routes/copilot-routes.ts b/src/web-server/routes/copilot-routes.ts
index 3d4bae9e..31cf897c 100644
--- a/src/web-server/routes/copilot-routes.ts
+++ b/src/web-server/routes/copilot-routes.ts
@@ -27,6 +27,18 @@ const router = Router();
 // Mount settings sub-routes
 router.use('/settings', copilotSettingsRoutes);
 
+function parseRequiredModel(value: unknown): string | null {
+  if (typeof value !== 'string') return null;
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : null;
+}
+
+function parseOptionalModel(value: unknown): string | undefined {
+  if (typeof value !== 'string') return undefined;
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : undefined;
+}
+
 /**
  * GET /api/copilot/status - Get Copilot status (auth + daemon + install info)
  */
@@ -75,31 +87,133 @@ router.get('/config', (_req: Request, res: Response): void => {
 router.put('/config', (req: Request, res: Response): void => {
   try {
     const updates = req.body;
+    if (!updates || typeof updates !== 'object' || Array.isArray(updates)) {
+      res.status(400).json({ error: 'Request body must be a JSON object' });
+      return;
+    }
+    const payload = updates as Record<string, unknown>;
+
+    if ('port' in payload) {
+      if (typeof payload.port !== 'number' || !Number.isInteger(payload.port)) {
+        res.status(400).json({ error: 'port must be an integer' });
+        return;
+      }
+      if (payload.port < 1 || payload.port > 65535) {
+        res.status(400).json({ error: 'port must be between 1 and 65535' });
+        return;
+      }
+    }
+
+    if ('enabled' in payload && typeof payload.enabled !== 'boolean') {
+      res.status(400).json({ error: 'enabled must be a boolean' });
+      return;
+    }
+
+    if ('auto_start' in payload && typeof payload.auto_start !== 'boolean') {
+      res.status(400).json({ error: 'auto_start must be a boolean' });
+      return;
+    }
+
+    if ('wait_on_limit' in payload && typeof payload.wait_on_limit !== 'boolean') {
+      res.status(400).json({ error: 'wait_on_limit must be a boolean' });
+      return;
+    }
+
+    if (
+      'account_type' in payload &&
+      payload.account_type !== 'individual' &&
+      payload.account_type !== 'business' &&
+      payload.account_type !== 'enterprise'
+    ) {
+      res.status(400).json({ error: 'account_type must be individual, business, or enterprise' });
+      return;
+    }
+
+    if ('rate_limit' in payload) {
+      if (payload.rate_limit !== null) {
+        if (typeof payload.rate_limit !== 'number' || !Number.isInteger(payload.rate_limit)) {
+          res.status(400).json({ error: 'rate_limit must be an integer or null' });
+          return;
+        }
+        if (payload.rate_limit < 0) {
+          res.status(400).json({ error: 'rate_limit must be >= 0 or null' });
+          return;
+        }
+      }
+    }
+
+    const normalizedModel = parseRequiredModel(payload.model);
+    if ('model' in payload && !normalizedModel) {
+      res.status(400).json({ error: 'model must be a non-empty string' });
+      return;
+    }
+
+    if (
+      'opus_model' in payload &&
+      payload.opus_model !== undefined &&
+      payload.opus_model !== null &&
+      typeof payload.opus_model !== 'string'
+    ) {
+      res.status(400).json({ error: 'opus_model must be a string' });
+      return;
+    }
+
+    if (
+      'sonnet_model' in payload &&
+      payload.sonnet_model !== undefined &&
+      payload.sonnet_model !== null &&
+      typeof payload.sonnet_model !== 'string'
+    ) {
+      res.status(400).json({ error: 'sonnet_model must be a string' });
+      return;
+    }
+
+    if (
+      'haiku_model' in payload &&
+      payload.haiku_model !== undefined &&
+      payload.haiku_model !== null &&
+      typeof payload.haiku_model !== 'string'
+    ) {
+      res.status(400).json({ error: 'haiku_model must be a string' });
+      return;
+    }
+
     const config = loadOrCreateUnifiedConfig();
 
     // Merge updates with existing config
     config.copilot = {
-      enabled: updates.enabled ?? config.copilot?.enabled ?? DEFAULT_COPILOT_CONFIG.enabled,
+      enabled:
+        (payload.enabled as boolean) ?? config.copilot?.enabled ?? DEFAULT_COPILOT_CONFIG.enabled,
       auto_start:
-        updates.auto_start ?? config.copilot?.auto_start ?? DEFAULT_COPILOT_CONFIG.auto_start,
-      port: updates.port ?? config.copilot?.port ?? DEFAULT_COPILOT_CONFIG.port,
+        (payload.auto_start as boolean) ??
+        config.copilot?.auto_start ??
+        DEFAULT_COPILOT_CONFIG.auto_start,
+      port: (payload.port as number) ?? config.copilot?.port ?? DEFAULT_COPILOT_CONFIG.port,
       account_type:
-        updates.account_type ?? config.copilot?.account_type ?? DEFAULT_COPILOT_CONFIG.account_type,
+        (payload.account_type as 'individual' | 'business' | 'enterprise') ??
+        config.copilot?.account_type ??
+        DEFAULT_COPILOT_CONFIG.account_type,
       rate_limit:
-        updates.rate_limit !== undefined
-          ? updates.rate_limit
+        payload.rate_limit !== undefined
+          ? (payload.rate_limit as number | null)
           : (config.copilot?.rate_limit ?? DEFAULT_COPILOT_CONFIG.rate_limit),
       wait_on_limit:
-        updates.wait_on_limit ??
+        (payload.wait_on_limit as boolean) ??
         config.copilot?.wait_on_limit ??
         DEFAULT_COPILOT_CONFIG.wait_on_limit,
-      model: updates.model ?? config.copilot?.model ?? DEFAULT_COPILOT_CONFIG.model,
+      model: normalizedModel ?? config.copilot?.model ?? DEFAULT_COPILOT_CONFIG.model,
       opus_model:
-        updates.opus_model !== undefined ? updates.opus_model : config.copilot?.opus_model,
+        'opus_model' in payload
+          ? parseOptionalModel(payload.opus_model)
+          : config.copilot?.opus_model,
       sonnet_model:
-        updates.sonnet_model !== undefined ? updates.sonnet_model : config.copilot?.sonnet_model,
+        'sonnet_model' in payload
+          ? parseOptionalModel(payload.sonnet_model)
+          : config.copilot?.sonnet_model,
       haiku_model:
-        updates.haiku_model !== undefined ? updates.haiku_model : config.copilot?.haiku_model,
+        'haiku_model' in payload
+          ? parseOptionalModel(payload.haiku_model)
+          : config.copilot?.haiku_model,
     };
 
     saveUnifiedConfig(config);
diff --git a/tests/unit/copilot/copilot-command-aliases.test.ts b/tests/unit/copilot/copilot-command-aliases.test.ts
index 4cc4b7ae..cb8c19ca 100644
--- a/tests/unit/copilot/copilot-command-aliases.test.ts
+++ b/tests/unit/copilot/copilot-command-aliases.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from 'bun:test';
 import {
   COPILOT_SUBCOMMANDS,
   COPILOT_SUBCOMMAND_TOKENS,
+  isLikelyCopilotFlagAlias,
   normalizeCopilotSubcommand,
 } from '../../../src/copilot/constants';
 
@@ -23,6 +24,13 @@ describe('copilot command aliases', () => {
     expect(normalizeCopilotSubcommand('unknown')).toBe('unknown');
   });
 
+  it('detects likely mistyped command aliases for entrypoint routing', () => {
+    expect(isLikelyCopilotFlagAlias('--statu')).toBe(true);
+    expect(isLikelyCopilotFlagAlias('--enabl')).toBe(true);
+    expect(isLikelyCopilotFlagAlias('--print')).toBe(false);
+    expect(isLikelyCopilotFlagAlias('--')).toBe(false);
+  });
+
   it('exposes complete routing token list for ccs entrypoint', () => {
     for (const subcommand of COPILOT_SUBCOMMANDS) {
       expect(COPILOT_SUBCOMMAND_TOKENS).toContain(subcommand);
diff --git a/tests/unit/copilot/copilot-daemon.test.ts b/tests/unit/copilot/copilot-daemon.test.ts
index ad8e6b6f..fda794fd 100644
--- a/tests/unit/copilot/copilot-daemon.test.ts
+++ b/tests/unit/copilot/copilot-daemon.test.ts
@@ -4,7 +4,8 @@ import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
 import { spawn } from 'child_process';
-import { isDaemonRunning, stopDaemon } from '../../../src/copilot/copilot-daemon';
+import { isDaemonRunning, startDaemon, stopDaemon } from '../../../src/copilot/copilot-daemon';
+import { DEFAULT_COPILOT_CONFIG } from '../../../src/config/unified-config-types';
 import { getCcsDir } from '../../../src/utils/config-manager';
 
 const activeServers: http.Server[] = [];
@@ -58,7 +59,18 @@ async function createServer(
   return address.port;
 }
 
+function writeCopilotPortConfig(port: number): void {
+  const configPath = path.join(getCcsDir(), 'config.yaml');
+  fs.mkdirSync(path.dirname(configPath), { recursive: true });
+  fs.writeFileSync(configPath, `version: 8\ncopilot:\n  port: ${port}\n`);
+}
+
 describe('copilot daemon health detection', () => {
+  it('returns false for invalid port inputs', async () => {
+    expect(await isDaemonRunning(0)).toBe(false);
+    expect(await isDaemonRunning(65536)).toBe(false);
+  });
+
   it('returns false when no daemon is running on port', async () => {
     const running = await isDaemonRunning(19998);
     expect(running).toBe(false);
@@ -103,10 +115,26 @@ describe('copilot daemon health detection', () => {
     const running = await isDaemonRunning(port);
     expect(running).toBe(false);
   });
+
+  it('fails fast when startDaemon is called with invalid port', async () => {
+    const result = await startDaemon({
+      ...DEFAULT_COPILOT_CONFIG,
+      port: 70000,
+    });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('Invalid Copilot daemon port');
+  });
 });
 
 describe('copilot daemon stop safety', () => {
-  it('does not terminate unrelated process from stale PID file', async () => {
+  it('returns failure when stale PID points to unrelated process but daemon is still live', async () => {
+    const port = await createServer((_req, res) => {
+      res.writeHead(200, { 'Content-Type': 'text/plain' });
+      res.end('Server running');
+    });
+
+    writeCopilotPortConfig(port);
+
     const unrelatedProcess = spawn(process.execPath, ['-e', 'setInterval(() => {}, 1000);'], {
       detached: true,
       stdio: 'ignore',
@@ -125,9 +153,42 @@ describe('copilot daemon stop safety', () => {
 
     try {
       const result = await stopDaemon();
-      if (!result.success) {
-        expect(result.error).toContain('unable to verify daemon ownership');
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('daemon is still responding on port');
+
+      // Unrelated process should still be alive.
+      expect(() => process.kill(unrelatedPid, 0)).not.toThrow();
+    } finally {
+      try {
+        process.kill(unrelatedPid, 'SIGTERM');
+      } catch {
+        // Process already exited.
       }
+    }
+  });
+
+  it('does not terminate unrelated process from stale PID file', async () => {
+    writeCopilotPortConfig(65534);
+
+    const unrelatedProcess = spawn(process.execPath, ['-e', 'setInterval(() => {}, 1000);'], {
+      detached: true,
+      stdio: 'ignore',
+    });
+    unrelatedProcess.unref();
+
+    const unrelatedPid = unrelatedProcess.pid;
+    expect(unrelatedPid).toBeDefined();
+    if (!unrelatedPid) {
+      throw new Error('Failed to spawn unrelated process');
+    }
+
+    const pidFile = path.join(getCcsDir(), 'copilot', 'daemon.pid');
+    fs.mkdirSync(path.dirname(pidFile), { recursive: true });
+    fs.writeFileSync(pidFile, String(unrelatedPid));
+
+    try {
+      const result = await stopDaemon();
+      expect(result.success).toBe(true);
 
       // Unrelated process should still be alive.
       expect(() => process.kill(unrelatedPid, 0)).not.toThrow();