feat: support binding dev server to all network interfaces via --host

[hackxixi]

Summary

• Adds --host support to bun run dev so the dev server can bind to any network interface (e.g. bun run dev -- --host 0.0.0.0), enabling LAN access from phones/tablets/remote machines.
• Fixes a lurking bug in wsTransport.ts where the WS fallback URL used window.location.port (the Vite web port, 5733) instead of the actual WS server port (3773), breaking external connections.
• Also conditionalises hmr.host so hot-module reloading works for remote devices (previously pinned to localhost, causing HMR to fail on LAN clients).
• Includes fixes for four pre-existing TypeScript errors that were hidden by Turbo's early-exit behaviour; they would block bun typecheck once the first failure was resolved.

Changes

Host binding (5 files):

• turbo.json — add PEAKCODE_HOST and VITE_WS_PORT to globalEnv so child processes receive them
• scripts/dev-runner.ts — compute isWildcardHost; for wildcard binds inject VITE_WS_PORT and clear VITE_WS_URL (browser constructs the URL from window.location.hostname + port); for explicit hosts set VITE_WS_URL directly
• apps/web/vite.config.ts — bind server.host to PEAKCODE_HOST; define VITE_WS_PORT; conditionalise hmr.host (omit for wildcard so remote HMR works, pin to localhost for local/Electron)
• apps/web/src/wsTransport.ts — fix fallback URL to use VITE_WS_PORT instead of window.location.port
• apps/web/src/vite-env.d.ts — declare VITE_WS_URL and VITE_WS_PORT in ImportMetaEnv

Pre-existing typecheck fixes (4 files):

• apps/server/src/anthropicAdapter.ts — narrow error-body via Record<string, unknown> before accessing .error (didn't exist on OpenAIChatResponse)
• apps/server/src/gateway.ts — add explicit return-type annotation on flatMap callback (union inferred too narrowly)
• apps/server/src/http.ts — cast entry as string | undefined after Array.isArray guard (ReadonlyArray is not narrowed out)
• apps/web/src/routes/_chat.settings.tsx — pass disabled={props.disabled ?? false} to avoid exactOptionalPropertyTypes mismatch

Test plan

• bun fmt && bun lint && bun typecheck — all pass (verified locally)
• bun.lock — zero changes (verified: git diff --stat bun.lock is empty)
• Local access unchanged: bun run dev (no flags) still serves on localhost:5733
• LAN access: bun run dev -- --host 0.0.0.0, open http://<LAN_IP>:5733 from another device — app loads and WS connects (ws://<LAN_IP>:3773/ws status 101)
• Remote HMR: edit a source file while a remote device has the app open — hot update appears without page reload

https://claude.ai/code/session_01B95xcqmnLyWiAhApQdjtLC

[jwangkun]

❌ Changes Requested

This PR has merge conflicts with the base branch and cannot be merged as-is.

Issues:

1. Merge status: CONFLICTING — Branch has conflicts with main that must be resolved before merging.
2. Description incomplete — Missing ## Why section per CONTRIBUTING.md conventions.
3. Diff size: 242 lines — Exceeds the <200 line target; consider splitting if possible.

Action Required:

• Resolve merge conflicts by rebasing onto main
• Add a ## Why section to the PR description
• Consider splitting the PR if feasible

Please update and re-request review.