port: 8000/8001 -> 8099/8098 everywhere ...

navi runs on shared servers where 8000/8001 are usually taken. New
defaults: API 8099, navi_ui MCP 8098. Touched: config defaults
(navi_port, navi_ui_mcp_port, public_url, gnauth_redirect_uri),
navi-server launcher docs, env.template/.env.example, install.sh
health-check fallback, terminal client base_url, webclient dev configs
(useWebSocket, contentLinks, vite proxy), android url hint, docs.
Also made the navi_ui FastMCP constructor port settings-driven instead
of a hardcoded 8001 (it was overridden at start anyway).

deploy: one-command server bundle (dockerized postgres + systemd) ...

deploy/install.sh — everything in one command: prerequisite checks,
.env provisioning from env.template (generated DB password), dockerized
PostgreSQL (pgvector image, restart: always, bound to 127.0.0.1, vector
+ pg_trgm extensions), venv + pip install, a systemd unit with
Restart=always (the server lives from installation, per the roadmap
where these modules become each other's subagents), health check, and
navi-code/navi-server symlinks into PATH. Idempotent — safe to re-run.

Default deployed shape: web UI off, auth off, terminal client only.
Re-enabling the web panel later is editing .env + restart — nothing is
removed from the tree.

The deploy branch (next commit set) differs from master only by a
filled-in .env.