feat(thinking): complete thinking UX/DX for all providers

- Fix codex off-mode bug: add disableEffort to CodexReasoningProxy
  so mode=off actually skips reasoning injection
- Add CCS_THINKING env var (priority: flag > env > config)
- Add startup feedback: [i] Thinking: <level> (<source>)
- Add ccs config thinking CLI subcommand with --mode, --override,
  --tier, --provider-override, --clear-override
- Dashboard: add manual override selector when mode=manual
- Dashboard: add provider overrides collapsible section
- Dashboard: update info box with CCS_THINKING env var docs
- Update help-command.ts with CCS_THINKING and config thinking

Closes #583

src/cliproxy/codex-reasoning-proxy.ts

@@ -25,6 +25,8 @@ export interface CodexReasoningProxyConfig {
    * Example: '/api/provider/codex' will transform '/api/provider/codex/v1/messages' to '/v1/messages'
    */
   stripPathPrefix?: string;
+  /** When true, skip reasoning effort injection entirely (thinking mode: off) */
+  disableEffort?: boolean;
 }
 
 const EXTENDED_CONTEXT_SUFFIX_REGEX = /\[1m\]$/i;
@@ -147,7 +149,12 @@ export class CodexReasoningProxy {
   private readonly config: Required<
     Pick<
       CodexReasoningProxyConfig,
-      'upstreamBaseUrl' | 'verbose' | 'timeoutMs' | 'defaultEffort' | 'traceFilePath'
+      | 'upstreamBaseUrl'
+      | 'verbose'
+      | 'timeoutMs'
+      | 'defaultEffort'
+      | 'traceFilePath'
+      | 'disableEffort'
     >
   > &
     Pick<CodexReasoningProxyConfig, 'modelMap' | 'stripPathPrefix'>;
@@ -170,6 +177,7 @@ export class CodexReasoningProxy {
       defaultEffort: config.defaultEffort ?? 'medium',
       traceFilePath: config.traceFilePath ?? '',
       stripPathPrefix: config.stripPathPrefix,
+      disableEffort: config.disableEffort ?? false,
     };
     this.modelEffort = buildCodexModelEffortMap(this.config.modelMap, this.config.defaultEffort);
   }
@@ -330,6 +338,20 @@ export class CodexReasoningProxy {
         ? stripExtendedContextSuffix(originalModel)
         : null;
 
+      // When effort is disabled (thinking mode: off), strip model suffix but don't inject reasoning
+      if (this.config.disableEffort) {
+        const suffixParsed = normalizedRequestModel
+          ? parseModelEffortSuffix(normalizedRequestModel)
+          : null;
+        const upstreamModel = suffixParsed?.upstreamModel ?? normalizedRequestModel;
+        const forwarded =
+          upstreamModel && isRecord(parsed) ? { ...parsed, model: upstreamModel } : parsed;
+
+        this.log(`[disabled] model=${originalModel ?? 'null'} -> passthrough (no reasoning)`);
+        await this.forwardJson(req, res, fullUpstreamUrl, forwarded);
+        return;
+      }
+
       // Support "model aliases" like `gpt-5.2-codex-xhigh` by translating to:
       // - upstream model: `gpt-5.2-codex`
       // - reasoning.effort: `xhigh`

src/cliproxy/executor/index.ts

@@ -49,7 +49,7 @@ import {
   installWebSearchHook,
   displayWebSearchStatus,
 } from '../../utils/websearch-manager';
-import { loadOrCreateUnifiedConfig } from '../../config/unified-config-loader';
+import { loadOrCreateUnifiedConfig, getThinkingConfig } from '../../config/unified-config-loader';
 import { installImageAnalyzerHook } from '../../utils/hooks';
 import { HttpsTunnelProxy } from '../https-tunnel-proxy';
 import { isKiroAuthMethod, KiroAuthMethod, normalizeKiroAuthMethod } from '../auth/auth-types';
@@ -354,7 +354,20 @@ export async function execClaudeWithCLIProxy(
     process.exit(1);
   }
 
-  const thinkingOverride = thinkingParse.value;
+  // Priority: CLI flag > CCS_THINKING env var > config.yaml
+  let thinkingOverride = thinkingParse.value;
+  let thinkingSource: 'flag' | 'env' | 'config' | undefined =
+    thinkingOverride !== undefined ? 'flag' : undefined;
+
+  if (thinkingOverride === undefined && process.env.CCS_THINKING) {
+    const envVal = process.env.CCS_THINKING.trim();
+    if (envVal) {
+      // Parse same as CLI: integer string → number, else string
+      thinkingOverride = /^-?\d+$/.test(envVal) ? Number.parseInt(envVal, 10) : envVal;
+      thinkingSource = 'env';
+    }
+  }
+
   if (thinkingParse.duplicateDisplays.length > 0) {
     console.warn(
       `[!] Multiple reasoning flags detected. Using first occurrence: ${thinkingParse.sourceDisplay}`
@@ -804,10 +817,18 @@ export async function execClaudeWithCLIProxy(
           process.env.CCS_CODEX_REASONING_TRACE === '1' ||
           process.env.CCS_CODEX_REASONING_TRACE === 'true';
         const stripPathPrefix = useRemoteProxy ? '/api/provider/codex' : undefined;
+        const thinkingCfg = getThinkingConfig();
+        const codexThinkingOff =
+          (thinkingCfg.mode === 'off' && thinkingOverride === undefined) ||
+          thinkingOverride === 'off' ||
+          (thinkingOverride === undefined &&
+            thinkingCfg.mode === 'manual' &&
+            thinkingCfg.override === 'off');
         codexReasoningProxy = new CodexReasoningProxy({
           upstreamBaseUrl: postSanitizationBaseUrl,
           verbose,
           defaultEffort: 'medium',
+          disableEffort: codexThinkingOff,
           traceFilePath: traceEnabled ? path.join(getCcsDir(), 'codex-reasoning-proxy.log') : '',
           modelMap: {
             defaultModel: initialEnvVars.ANTHROPIC_MODEL,
@@ -875,6 +896,33 @@ export async function execClaudeWithCLIProxy(
   const webSearchEnv = getWebSearchHookEnv();
   logEnvironment(env, webSearchEnv, verbose);
 
+  // 11b. Print thinking status feedback (TTY only, non-piped sessions)
+  if (process.stderr.isTTY) {
+    const thinkingCfgStatus = getThinkingConfig();
+    let thinkingLabel: string;
+    let sourceLabel: string;
+
+    if (thinkingOverride === 'off' || thinkingCfgStatus.mode === 'off') {
+      thinkingLabel = 'off';
+      sourceLabel =
+        thinkingSource === 'flag' ? 'flag' : thinkingSource === 'env' ? 'env' : 'config';
+    } else if (thinkingSource === 'flag') {
+      thinkingLabel = String(thinkingOverride);
+      sourceLabel = `flag: ${thinkingParse.sourceDisplay}`;
+    } else if (thinkingSource === 'env') {
+      thinkingLabel = String(thinkingOverride);
+      sourceLabel = 'env: CCS_THINKING';
+    } else if (thinkingCfgStatus.mode === 'manual' && thinkingCfgStatus.override !== undefined) {
+      thinkingLabel = String(thinkingCfgStatus.override);
+      sourceLabel = 'config: manual';
+    } else {
+      thinkingLabel = thinkingCfgStatus.mode === 'auto' ? 'auto' : 'default';
+      sourceLabel = 'config: auto';
+    }
+
+    console.error(`[i] Thinking: ${thinkingLabel} (${sourceLabel})`);
+  }
+
   // 12. Filter CCS-specific flags before passing to Claude CLI
   const ccsFlags = [
     '--auth',