feat: run ftl serve as part of ftl dev

[wesbillman]

Fixes #979

New help exposes embedded serve- flags:

ftl dev --help

Usage: ftl dev [<base-dir>]

Watch a directory for FTL modules and hot reload them.

Arguments:
  [<base-dir>]    Directory to watch for FTL modules

Flags:
  -h, --help           Show context-sensitive help.
      --version        Show version.
      --config=FILE    Load configuration from TOML file.
      --endpoint=http://127.0.0.1:8892
                       FTL endpoint to bind/connect to ($FTL_ENDPOINT).
      --authenticators=HOST=EXE,…
                       Authenticators to use for FTL endpoints ($FTL_AUTHENTICATORS).

Logging:
  --log-level=info    Log level ($LOG_LEVEL).
  --log-json          Log in JSON format ($LOG_JSON).

Command flags:
      --watch=500ms            Watch template directory at this frequency and regenerate
                               on change.
      --failure-delay=500ms    Delay before retrying a failed deploy.
      --reconnect-delay=1s     Delay before attempting to reconnect to FTL.
      --exit-after-deploy      Exit after all modules are deployed successfully.
      --no-serve               Do not start the FTL server.
      --serve-bind=http://localhost:8892
                               Starting endpoint to bind to and advertise to. Each
                               controller and runner will increment the port by 1
      --serve-allow-origins=SERVE-ALLOW-ORIGINS,...
                               Allow CORS requests to ingress endpoints from these origins
                               ($FTL_CONTROLLER_ALLOW_ORIGIN).
      --serve-db-port=54320    Port to use for the database.
      --serve-recreate         Recreate the database even if it already exists.
  -c, --serve-controllers=1    Number of controllers to start.
  -r, --serve-runners=0        Number of runners to start.
      --serve-background       Run in the background.
      --serve-stop             Stop the running FTL instance.

ftl dev with server and flags

ftl dev examples/go --serve-recreate

info: Starting FTL with 1 controller(s) and 0 runner(s)
warn: Detected change in +/Users/wesbillman/dev/ftl/examples/go/echo/echo.go, rebuilding...
error: Error deploying module /Users/wesbillman/dev/ftl/examples/go/echo. Will retry: module "time" not found
warn: Detected change in +/Users/wesbillman/dev/ftl/examples/go/time/time.go, rebuilding...
info:time: Building module
info:controller0: Web console available at: http://localhost:5173
info: Preparing module 'time' for deployment
info: Successfully created deployment time-e0368491b5
info:echo: Building module
info: Preparing module 'echo' for deployment
info: Successfully created deployment echo-092543e753

ftl dev without server

ftl dev examples/go --no-serve

warn: Detected change in +/Users/wesbillman/dev/ftl/examples/go/echo/go.sum, rebuilding...
error: Error deploying module /Users/wesbillman/dev/ftl/examples/go/echo. Will retry: module "time" not found
warn: Detected change in +/Users/wesbillman/dev/ftl/examples/go/time/go.mod, rebuilding...
info:time: Building module
info: Preparing module 'time' for deployment
error: Error deploying module /Users/wesbillman/dev/ftl/examples/go/time. Will retry: unavailable: dial tcp [::1]:8892: connect: connection refused
info:time: Building module
info: Preparing module 'time' for deployment
error: Error deploying module /Users/wesbillman/dev/ftl/examples/go/time. Will retry: unavailable: dial tcp [::1]:8892: connect: connection refused
error: Error deploying module /Users/wesbillman/dev/ftl/examples/go/echo. Will retry: module "time" not found