chore(repo): move current KarlDNS source to Gitea

Preserve the GitHub history and the newer deployed source from ct_134_karldns. Exclude runtime data, credentials, AppleDouble files and local backup copies. Make Gitea the canonical source for documentation, package metadata and project links.

karldns/routers/public.py

@@ -21,6 +21,7 @@ def index(request: Request, settings: SettingsDep) -> str:
 async def create_hostname(request: Request, settings: SettingsDep, service: ServiceDep) -> RedirectResponse:
     await request_form(request, settings)
     account = await run_in_threadpool(service.create_managed_account)
+    request.state.account_created = True
     return RedirectResponse(service.dashboard_url(account), status_code=303)
 
 
@@ -29,6 +30,77 @@ def healthz() -> str:
     return "ok"
 
 
+@router.get("/llms.txt", response_class=PlainTextResponse, include_in_schema=False)
+def llms_txt(settings: SettingsDep) -> str:
+    base_url = settings.public_base_url.rstrip("/")
+    return f"""# KarlDNS
+
+> KarlDNS provides anonymous dynamic DNS hostnames for routers and other clients,
+> with IPv4 (A) and IPv6 (AAAA) updates through an HTTP API and a private web dashboard.
+
+The public service base URL is `{base_url}`. Hostnames are generated under
+`{settings.hostname_suffix}`; clients cannot choose a custom hostname.
+Use HTTPS for this public service. No account login or API key is needed to create
+a hostname. Returned private URLs are bearer credentials: save them securely and
+never publish them, put them in shared logs, or substitute them into documentation.
+Examples below use placeholders, never working credentials.
+
+Create and activate a hostname:
+
+1. Send `POST {base_url}/api/v1/hostnames` with no request body. HTTP 201 JSON
+   includes `hostname`, `status` (initially `pending`), `dashboard_url`,
+   `registration_url`, and `update_url`. Save all three private URLs first.
+2. Call the returned `registration_url` using GET or POST, supplying the public
+   address as `myip` (IPv4) and/or `myipv6` (IPv6). HTTP 200 `good registered`
+   means activation succeeded. For FRITZ!Box, let the router perform registration
+   using `?myip=<ipaddr>` so the router supplies its own WAN address.
+3. After activation, configure the client with the returned `update_url`.
+   FRITZ!Box uses `?myip=<ipaddr>` and optionally `&myipv6=<ip6addr>`.
+   Do not send those router placeholders literally from a general HTTP client.
+
+Router requests use `GET` or `POST /api/v1/router/register/{{dashboard_secret}}`
+and `GET` or `POST /api/v1/router/update/{{update_slug}}`. They accept query
+parameters `myip`/`ipaddr` for IPv4 and `myipv6`/`ip6addr` for IPv6. POST also
+accepts JSON or URL-encoded bodies with string values. Prefer explicit public
+addresses; otherwise source-address detection is used. Never use a health probe
+to call these routes: even GET requests can change DNS.
+
+Updates return plain text: `good <address>` means changed, `nochg <address>`
+means already current. Invalid IPs return HTTP 400 `badip ...`; DNS-provider
+failures return HTTP 500 `911 ...`. Unknown, disabled, or unregistered update
+credentials return HTTP 404. Check HTTP status as well as the response body;
+back off on HTTP 429 or transient server failures instead of retrying rapidly.
+
+Read status with `GET /api/v1/hostnames/{{dashboard_secret}}`, using the last
+path segment of `dashboard_url`. Optional `history_limit` is 0 through 100
+(default 10). The response is JSON and includes lifecycle state and DNS addresses.
+Rotate an active hostname's update credential with
+`POST /api/v1/hostnames/{{dashboard_secret}}/rotate-update-url`; save and configure
+the returned replacement `update_url` immediately because the old one stops working.
+`DELETE /api/v1/hostnames/{{dashboard_secret}}` removes the hostname and its DNS
+records and returns HTTP 204. Delete only when the owner requests it.
+
+On the website, GET `/` displays the homepage; submitting its form creates a
+hostname and redirects to the private dashboard. Keep that dashboard URL: it is
+the management credential. Dashboard passwords protect only the web dashboard,
+not API access using the dashboard secret. Use the API for automation instead of
+scraping private pages. Unregistered hostnames are cleaned up automatically.
+GET `/healthz` is a read-only health check returning HTTP 200 `ok`.
+
+## API and Website
+
+- [OpenAPI schema]({base_url}/openapi.json): Machine-readable request and response definitions.
+- [API guide]({base_url}/docs): Human-readable API examples and router setup guidance.
+- [Homepage]({base_url}/): Create a hostname through the browser form.
+- [Health]({base_url}/healthz): Read-only service availability probe.
+
+## Optional
+
+- [Privacy]({base_url}/privacy): Data handling information.
+- [Project README](https://tea.karlcom.de/karl/karldns.de/raw/branch/main/README.md): Self-hosting and clients.
+"""
+
+
 @router.get("/privacy", response_class=HTMLResponse, include_in_schema=False)
 def privacy(settings: SettingsDep) -> str:
     return _render_privacy_page(settings)