feat: mobile UI scaffold + desktop build wiring + dev port scheme (17687/5179)

[johnnyhuy]

Summary

Two commits covering the mobile UI MVP, the desktop-shell build gap,
and a port scheme that gets the dev loop off Paseo / Vite / Metro defaults.

Mobile UI scaffold (feat(app): scaffold mobile UI for connect/sessions/transcript)

Three screens on top of @echohello/client:

• connect — manual ws:// endpoint + label, persists to AsyncStorage,
  drives SupaplaneClient.connect()
• sessions — workspace list grouped by freshness, tap to drill in
• session/[id] — transcript + composer (send / abort / start)
  bound to ClientCommand wire types

Shared infra:

• zustand connection-store owns a single SupaplaneClient instance,
  status, workspaces, sessions, and a per-session event buffer
• AsyncStorage v3 wrapper (setMany / removeMany) for the saved
  endpoint and TOFU-pinned server fingerprint
• Dark theme tokens, Button, TextField, ConnectionBanner

Bundler plumbing: metro.config.cjs declares explicit
watchFolders and nodeModulesPaths so Bun's hoisting doesn't trip
Metro when resolving app/ screens from a monorepo root.

Desktop build wiring + dev port scheme (chore(dev): wire desktop build + shift dev ports off 6767/5173)

The existing desktop/dev: electron . was broken — Electron's Node
couldn't load TS or follow .js import paths into .ts sources.
Now:

• packages/desktop/tsconfig.build.json emits ESM to dist/
• packages/desktop/package.json dev runs tsc then electron
• @echohello/server and @echohello/protocol exports point at
  dist/ so Electron's Node can resolve them. Run
  bun run build:server (or full bun run build) before
  desktop dev.
• daemon-keypair.ts: replaced require('node:crypto') with top-level
  randomBytes import so it builds cleanly to ESM.

Dev port scheme (verified against the IANA port list — the 17000–17999
range has only 10 registered ports; 5174–5189 are all unassigned):

Service	Before	After	Why
Daemon (HTTP+WS)	6767	17687	Sparse IANA range; visually echoes Paseo with a leading 1
Vite dev server	5173	5179	Adjacent to Vite default; sits in a quiet IANA zone

Verification

Manually ran the full stack end-to-end:

$ bun run typecheck        # clean
$ bun test                 # 44 pass, 2 pre-existing fails in connection-offer.test.ts
$ bun run lint             # 0 errors
$ bun run build            # clean

# End-to-end
$ cd packages/desktop && bun run dev  # builds dist + launches Electron
$ curl http://127.0.0.1:17687/api/health
{"status":"ok","serverId":"srv_uXWlD-VmFsmKkB66",...}
# Vite-served web renderer inside Electron opens a 'web-...' WS session
# back through the :5179 proxy

Env overrides remain available: SUPAPLANE_LISTEN_PORT,
SUPAPLANE_DAEMON_PORT, SUPAPLANE_WEB_PORT, VITE_PORT.

Test status

Package	Before	After
connection-offer.test.ts	2 fail	2 fail (pre-existing — these assert supaplane.run but the encoder produces supaplane.com; unrelated to this PR)
config.test.ts	1 fail	pass (was asserting default listenPort === 6767, updated to 17687)

Net: 3 → 2 pre-existing failures, 0 new failures.

Consequences

• @echohello/{protocol,server} exports now resolve to dist/
  rather than src/. Anyone importing these workspaces from Node
  (not via Bundler resolution) must run bun run build first.
  Mobile/Vite/web keep working via their bundler resolution.
• Vite default port moved off 5173. Any external tooling that
  hard-codes 5173 (browser bookmarks, scripts) needs to be updated
  to 5179.
• Daemon default port moved off 6767. The CLI defaults in
  cli/src/commands/daemon.ts still say 6767 in their help text
  (left intentionally — they're display strings); env override is
  available via --endpoint.

Testing

• bun run typecheck clean
• bun run build clean
• bun test (no new failures; one pre-existing failure now passes)
• Manual end-to-end: Vite (5179) + Electron-rendered web +
  embedded daemon (17687) — health endpoint responds, WS session opens
• Eyeball review requested for the dev-port choice + desktop
  exports flip