feat(cli): add global option to disable automatic session title changes

[chenbojian]

Summary

• Adds enableAutoTitle setting in ~/.hapi/settings.json (defaults to true)
• When set to false, the title instruction is omitted from system prompts (Claude, Codex, OpenCode) and the change_title MCP tool is not registered
• No changes to launcher files or web frontend — minimal, self-contained change

Support part of #271

Test plan

• Set "enableAutoTitle": false in ~/.hapi/settings.json → start a session → verify no title-change tool calls and no title instruction in prompt
• Remove setting or set true → verify behavior unchanged
• Run bun run typecheck in cli/ — passes
• Run bunx vitest run src/claude/utils/claudeSettings.test.ts — all 11 tests pass

[github-actions]

Review mode: initial

Findings

• [Major] enableAutoTitle=false does not fully disable automatic title changes outside Claude. The new guard removes the HTTP-side tool in cli/src/claude/utils/startHappyServer.ts:45, but Codex/OpenCode still launch the shared stdio bridge, and that bridge still unconditionally advertises change_title in cli/src/codex/happyMcpStdioBridge.ts:72. That leaves the tool visible and callable in the non-Claude modes this PR claims to cover.

Summary

• enableAutoTitle=false currently suppresses prompt text, but not end-to-end tool exposure for Codex/OpenCode.
• Not found in tests: coverage for the MCP bridge/tool advertisement path when enableAutoTitle is false.

Testing

• Not run (automation)

HAPI Bot

[github-actions]

[MAJOR] enableAutoTitle=false only removes the tool from the HTTP MCP server here. Codex and OpenCode still go through buildHapiMcpBridge(...), and cli/src/codex/happyMcpStdioBridge.ts:72 still unconditionally re-registers change_title, so those modes can still see and call the title tool.

Suggested fix:

const client = await ensureHttpClient();
const { tools } = await client.listTools();

if (tools.some((tool) => tool.name === 'change_title')) {
    server.registerTool<any, any>('change_title', {
        description: 'Change the title of the current chat session',
        title: 'Change Chat Title',
        inputSchema: changeTitleInputSchema,
    }, async (args: Record<string, unknown>) => {
        return client.callTool({ name: 'change_title', arguments: args });
    });
}

[chenbojian]

fixed in next commit

[github-actions]

Findings

• No actionable findings in the updated diff.

Summary

• Review mode: follow-up after new commits
• No new diff-attributable correctness, security, or maintainability issues found.
• Residual risk: not found in repo/docs/tests, targeted coverage for enableAutoTitle=false through the non-Claude launch paths touched here, especially cli/src/codex/happyMcpStdioBridge.ts:68, cli/src/opencode/opencodeLocalLauncher.ts:274, and cli/src/opencode/opencodeRemoteLauncher.ts:120.

Testing

• Not run (automation)

HAPI Bot