Make the workspace editor reachable through the sub-path proxy

code-server runs authenticateOrigin on every websocket and resolves the
request host as Forwarded, then X-Forwarded-Host, then Host. The forward
core put the public host into additional_headers, but the websockets
client already writes its own Host for the real TCP target and Headers
appends, so the handshake carried two Host lines; Node keeps the first
(the internal gateway:port), the origin check failed, and code-server
answered 403. Because the browser socket was accepted before the upstream
was dialled, that surfaced as a 101 followed by 1011 and the editor died
on "the workbench failed to connect to the server". Dialling first and
carrying the public host in the connect URI fixes both planes.

The two header builders that had drifted apart are now one core, so a
websocket carries the same client and forwarded headers as an HTTP
request. Responses stream instead of buffering whole, which is what makes
a large tunnel download cost constant memory and lets SSE work; byte
accounting moved onto the completion callback. Subprotocols negotiate,
the upstream client is reused across requests, and the path and query are
forwarded byte-exactly.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -269,7 +269,7 @@ Devii is also reachable over **Telegram** (one supervised long-poller subprocess
 
 - **No comments, no docstrings in source.** Code is self-documenting.
 - **Forbidden variable name patterns:** `_new`, `_old`, `_temp`, `_v2`, `better_`, `my_`, `the_`.
-- **Outbound HTTP goes through the stealth client only.** Never instantiate a bare `httpx.AsyncClient(...)`/`httpx.Client(...)` for outbound traffic - build it via `devplacepy.stealth.stealth_async_client(...)`/`stealth_sync_client(...)`. The async factory routes bytes through **`curl_cffi` (curl-impersonate, BoringSSL)** behind an `httpx` transport adapter, so TLS JA3/JA4 and the HTTP/2 fingerprint match Chrome 146 byte-for-byte; falls back to a pure-httpx Chrome-aligned transport if `curl_cffi` is missing. Applies to news, gateway upstream, Devii/DeepSearch/SEO fetch, gitea, push, attachments. SSRF-guarded fetches via `net_guard.guarded_async_client(...)` get the fingerprint automatically. Sole exception: `routers/proxy.py` relays the user's own headers verbatim. **Load-bearing gotcha:** cleartext `http://` is forced to HTTP/1.1 (`curl_transport.http_version_for`) - the Chrome-impersonation profile defaults to HTTP/2, but a plaintext origin has no TLS/ALPN to negotiate h2 and uvicorn (HTTP/1.1 only) returns `400 "Invalid HTTP request received."` once a cleartext HTTP/2 body crosses ~128KB. Every internal AI consumer calls `INTERNAL_GATEWAY_URL` = `http://localhost:<port>/openai/v1/...`, so without this override a large Devii turn (big system prompt + tool list) fails on every request. `https://` keeps the HTTP/2 default. `stealth_sync_client` stays pure-httpx Chrome-aligned (no curl_cffi sync adapter). **Never bolt a hand-written browser-header dict (UA/`sec-ch-ua`/`Sec-Fetch-*`) onto a `stealth_async_client`/`stealth_sync_client` call** - curl_cffi's impersonation already emits an internally-consistent Chrome 146 identity across TLS, UA, and Client Hints; a caller-supplied header set claiming a different Chrome version or platform creates a UA-vs-TLS-vs-Client-Hints mismatch that is a textbook anti-bot tripwire (this was a real bug in Devii's `fetch_url`/`http_request` tool, fixed by deleting its hardcoded Chrome-131 header block). `stealth.detect_consent_gate(html)` recognizes the common JS-redirect cookie-consent wall pattern (DPG Media's `nu.nl` and sibling sites, and generically any page gated behind a `decodeURIComponent(...)` callback referencing a "privacy gate"/`consent.js`) - reuse it wherever a fetched page's real content sits behind that gate rather than special-casing a domain. `stealth_transport`/`stealth_async_client`/`stealth_sync_client` all accept a `proxy=` override, defaulting to `stealth.configured_proxy_url()` (the admin-editable `outbound_proxy_url` site setting, falling back to `DEVPLACE_OUTBOUND_PROXY_URL` when the setting is unset) - this is the only real fix for a destination that blocks by IP/ASN reputation (e.g. reddit.com returns an identical "blocked by network security" page across every TLS/header fingerprint tried, confirmed by testing curl_cffi's full impersonation list - it is blocking the datacenter ASN outright, not fingerprinting the client).
+- **Outbound HTTP goes through the stealth client only.** Never instantiate a bare `httpx.AsyncClient(...)`/`httpx.Client(...)` for outbound traffic - build it via `devplacepy.stealth.stealth_async_client(...)`/`stealth_sync_client(...)`. The async factory routes bytes through **`curl_cffi` (curl-impersonate, BoringSSL)** behind an `httpx` transport adapter, so TLS JA3/JA4 and the HTTP/2 fingerprint match Chrome 146 byte-for-byte; falls back to a pure-httpx Chrome-aligned transport if `curl_cffi` is missing. Applies to news, gateway upstream, Devii/DeepSearch/SEO fetch, gitea, push, attachments. SSRF-guarded fetches via `net_guard.guarded_async_client(...)` get the fingerprint automatically. Sole exception: the reverse-proxy forwarding core `services/containers/forward.py` (and the three routers that call it - `routers/proxy.py`, `routers/tunnel.py`, the workspace editor route), which relays the user's own headers verbatim and therefore keeps a plain `httpx.AsyncClient`; bolting the Chrome identity onto it would overwrite the very headers it exists to forward. **Load-bearing gotcha:** cleartext `http://` is forced to HTTP/1.1 (`curl_transport.http_version_for`) - the Chrome-impersonation profile defaults to HTTP/2, but a plaintext origin has no TLS/ALPN to negotiate h2 and uvicorn (HTTP/1.1 only) returns `400 "Invalid HTTP request received."` once a cleartext HTTP/2 body crosses ~128KB. Every internal AI consumer calls `INTERNAL_GATEWAY_URL` = `http://localhost:<port>/openai/v1/...`, so without this override a large Devii turn (big system prompt + tool list) fails on every request. `https://` keeps the HTTP/2 default. `stealth_sync_client` stays pure-httpx Chrome-aligned (no curl_cffi sync adapter). **Never bolt a hand-written browser-header dict (UA/`sec-ch-ua`/`Sec-Fetch-*`) onto a `stealth_async_client`/`stealth_sync_client` call** - curl_cffi's impersonation already emits an internally-consistent Chrome 146 identity across TLS, UA, and Client Hints; a caller-supplied header set claiming a different Chrome version or platform creates a UA-vs-TLS-vs-Client-Hints mismatch that is a textbook anti-bot tripwire (this was a real bug in Devii's `fetch_url`/`http_request` tool, fixed by deleting its hardcoded Chrome-131 header block). `stealth.detect_consent_gate(html)` recognizes the common JS-redirect cookie-consent wall pattern (DPG Media's `nu.nl` and sibling sites, and generically any page gated behind a `decodeURIComponent(...)` callback referencing a "privacy gate"/`consent.js`) - reuse it wherever a fetched page's real content sits behind that gate rather than special-casing a domain. `stealth_transport`/`stealth_async_client`/`stealth_sync_client` all accept a `proxy=` override, defaulting to `stealth.configured_proxy_url()` (the admin-editable `outbound_proxy_url` site setting, falling back to `DEVPLACE_OUTBOUND_PROXY_URL` when the setting is unset) - this is the only real fix for a destination that blocks by IP/ASN reputation (e.g. reddit.com returns an identical "blocked by network security" page across every TLS/header fingerprint tried, confirmed by testing curl_cffi's full impersonation list - it is blocking the datacenter ASN outright, not fingerprinting the client).
 - **Form validation is Pydantic-native.** Routers declare `data: Annotated[SomeForm, Form()]` (models in `models.py`); the global `RequestValidationError` handler re-renders auth pages with messages (400) or redirects other routes. Read raw `await request.form()` only when also reading an uploaded file alongside a model.
 - **`RedirectResponse(url=..., status_code=302)`** - always pass `status_code` as an integer literal, never `status.HTTP_302_FOUND`.
 - **Ownership checks:** compare `resource["user_uid"] == user["uid"]` before edit/delete (use `content.is_owner`). **Deletes additionally allow any admin:** `is_owner(...) or is_admin(user)` on every content delete endpoint, so an administrator may delete any member's content while members are limited to their own. Edits stay owner-only. Deletes are **soft** and cascade under one shared stamp - see `devplacepy/database/CLAUDE.md`.