Make CLI success output copy-paste-safe; add --serve, docs hub, key hygiene

A successful clone printed a bare, timestamped app path that wrapped mid-word
in the terminal, so users' `cd` failed and `npm install && npm run dev` ran in
the wrong directory — a confusing failure from a successful clone. Plus there
was no first-party "see it locally" path, no central docs page, "clone" was
conflated with `git clone`, and key hygiene wasn't stated.

CLI (compiler):
- Add compiler/src/cliSummary.ts: a copy-paste-safe success block on stderr — a
  single QUOTED `cd "<app>" && npm install && npm run dev` line that survives
  terminal wrapping — plus the AGENTS.md safe-to-edit pointers (content.ts,
  components/). The machine-readable {"event":"done",...} JSON stays on stdout.
- Add --serve (npm install + npm run dev in the generated app) and --open
  (also open the browser at the detected dev URL). Wired into single + multi.
- Add writeLatestPointer(): refresh a runs/<site>/latest symlink to the newest
  run so there's a stable, timestamp-free cd/script target. The reuse/regen
  scanners already filter to digit-prefixed run dirs, so `latest` is ignored.
- Tests: cliSummary (quoting, single-line command, Next/Vite roots, stable-path
  preference, --serve/--open hint) and runsLayout (symlink write + in-place
  refresh, timestamp-free stable path).

Docs:
- Add docs/README.md as a central documentation index.
- State prominently that ditto "cloning" = generating a codebase from a live
  URL, NOT `git clone` (no source repo required), in README + docs hub.
- Add "keys are secrets: use $DITTO_API_KEY, never inline/commit, rotate
  anytime" beside the key/auth examples in README + docs/SERVICE.md.
- Document --serve/--open and the latest symlink in README + compiler/README.

Note: the live ditto.site/docs web route and the dashboard's inline-token
snippet live in the marketing-site repo and still need a change there.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

compiler/README.md

@@ -16,6 +16,8 @@ npm install
 npx playwright install chromium
 
 npm run clone -- https://example.com/
+npm run clone -- https://example.com/ --serve   # then npm install + npm run dev
+npm run clone -- https://example.com/ --open    # ...and open the browser too
 npm run clone -- https://example.com/ --mode=multi --styling=tailwind
 npm run clone -- https://example.com/ --mode=single --framework=vite
 npm run clone-site -- https://example.com/
@@ -34,6 +36,13 @@ npm run typecheck
 Root-level scripts forward to these commands, so `npm run clone -- <url>` works
 from the repository root too.
 
+("Clone" here = generating a codebase from a live URL, not `git clone`; no source
+repo required.) On success the CLI prints a copy-paste-safe summary: a single
+quoted `cd … && npm install && npm run dev` line plus safe-to-edit pointers. Pass
+`--serve` to run install + dev automatically, or `--open` to also launch the
+browser. Without `--out`, a `runs/<site>/latest` symlink always points at the
+newest run so paths aren't timestamp-fragile.
+
 Multi-page generation defaults to the fast no-validation path. Use `--validate`
 when the clone command itself should run the full build/render/gates QA pass, or
 run `validate-site` separately. `--concurrency` controls source route capture;