phase-40: Gemini + Claude provider adapters

Phase 40 PRD (docs/CONTROL_PLANE_PRD.md:82-83) listed:
  - crates/aibridge/src/providers/gemini.rs
  - crates/aibridge/src/providers/claude.rs

Neither existed. Landing both now, in gateway/src/v1/ (matches the
existing ollama.rs + openrouter.rs sibling pattern — aibridge's
providers/ is for the adapter *trait* abstractions, v1/ holds the
concrete /v1/chat dispatchers that know the wire format).

gemini.rs:
  - POST https://generativelanguage.googleapis.com/v1beta/models/
    {model}:generateContent?key=<API_KEY>
  - Auth: query-string key (not bearer)
  - Maps messages → contents+parts (Gemini's wire shape),
    extracts from candidates[0].content.parts[0].text
  - 3 tests: key resolution, body serialization (camelCase
    generationConfig + maxOutputTokens), prefix-strip

claude.rs:
  - POST https://api.anthropic.com/v1/messages
  - Auth: x-api-key header + anthropic-version: 2023-06-01
  - Carries system prompt in top-level `system` field (not
    messages[]). Extracts from content[0].text where type=="text"
  - 4 tests: key resolution, body serialization with/without
    system field, prefix-strip

v1/mod.rs:
  + V1State.gemini_key + claude_key Option<String>
  + resolve_provider() strips "gemini/" and "claude/" prefixes
  + /v1/chat dispatcher handles "gemini" + "claude"/"anthropic"
  + 2 new resolve_provider tests (prefix + strip per adapter)

main.rs:
  + Construct both keys at startup via resolve_*_key() helpers.
    Missing keys log at debug (not warn) since these are optional
    providers — unlike OpenRouter which is the rescue rung.

Every /v1/chat error path mirrors the existing pattern:
  - 503 SERVICE_UNAVAILABLE when key isn't configured
  - 502 BAD_GATEWAY with the provider's error text when the
    upstream call fails
  - Response shape always the OpenAI-compatible ChatResponse

Workspace warnings still at 0. 9 new tests pass.

Pre-existing test failure `executor_prompt_includes_surfaced_
candidates` at execution_loop/mod.rs:1550 is unrelated (fails on
pristine HEAD too — PR fixture divergence).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/gateway/src/v1/mod.rs

@@ -14,6 +14,8 @@
 pub mod ollama;
 pub mod ollama_cloud;
 pub mod openrouter;
+pub mod gemini;
+pub mod claude;
 pub mod langfuse_trace;
 pub mod respond;
 pub mod truth;
@@ -42,6 +44,14 @@ pub struct V1State {
     /// provider="openrouter" calls 503 rather than attempt. Same key
     /// sourcing as LLM Team UI so the two share one API quota.
     pub openrouter_key: Option<String>,
+    /// Gemini API key (Google Generative Language). Loaded at startup
+    /// via `gemini::resolve_gemini_key()`. None = provider="gemini"
+    /// calls 503. Phase 40 deliverable.
+    pub gemini_key: Option<String>,
+    /// Anthropic Claude API key. Loaded at startup via
+    /// `claude::resolve_claude_key()`. None = provider="claude" calls
+    /// 503. Phase 40 deliverable.
+    pub claude_key: Option<String>,
     /// Phase 40 early deliverable — Langfuse client. None = tracing
     /// disabled (keys missing or container unreachable). Traces are
     /// fire-and-forget: never block the response path.
@@ -159,6 +169,12 @@ fn resolve_provider(req: &ChatRequest) -> (String, String) {
     if let Some(rest) = req.model.strip_prefix("cloud/") {
         return ("ollama_cloud".to_string(), rest.to_string());
     }
+    if let Some(rest) = req.model.strip_prefix("gemini/") {
+        return ("gemini".to_string(), rest.to_string());
+    }
+    if let Some(rest) = req.model.strip_prefix("claude/") {
+        return ("claude".to_string(), rest.to_string());
+    }
     ("ollama".to_string(), req.model.clone())
 }
 
@@ -210,6 +226,18 @@ mod resolve_provider_tests {
         let r = mk_req(Some("openrouter"), "openrouter/openai/gpt-4o-mini");
         assert_eq!(resolve_provider(&r), ("openrouter".into(), "openrouter/openai/gpt-4o-mini".into()));
     }
+
+    #[test]
+    fn gemini_prefix_infers_and_strips() {
+        let r = mk_req(None, "gemini/gemini-2.0-flash");
+        assert_eq!(resolve_provider(&r), ("gemini".into(), "gemini-2.0-flash".into()));
+    }
+
+    #[test]
+    fn claude_prefix_infers_and_strips() {
+        let r = mk_req(None, "claude/claude-3-5-sonnet-latest");
+        assert_eq!(resolve_provider(&r), ("claude".into(), "claude-3-5-sonnet-latest".into()));
+    }
 }
 
 async fn chat(
@@ -273,10 +301,34 @@ async fn chat(
                 .map_err(|e| (StatusCode::BAD_GATEWAY, format!("openrouter: {e}")))?;
             (r, "openrouter".to_string())
         }
+        "gemini" => {
+            // Phase 40 provider adapter. Google Generative Language
+            // API via query-string key auth (not bearer).
+            let key = state.gemini_key.as_deref().ok_or((
+                StatusCode::SERVICE_UNAVAILABLE,
+                "GEMINI_API_KEY not configured".to_string(),
+            ))?;
+            let r = gemini::chat(key, &*req_for_adapter)
+                .await
+                .map_err(|e| (StatusCode::BAD_GATEWAY, format!("gemini: {e}")))?;
+            (r, "gemini".to_string())
+        }
+        "claude" | "anthropic" => {
+            // Phase 40 provider adapter. Anthropic Messages API via
+            // x-api-key header + anthropic-version:2023-06-01.
+            let key = state.claude_key.as_deref().ok_or((
+                StatusCode::SERVICE_UNAVAILABLE,
+                "ANTHROPIC_API_KEY not configured".to_string(),
+            ))?;
+            let r = claude::chat(key, &*req_for_adapter)
+                .await
+                .map_err(|e| (StatusCode::BAD_GATEWAY, format!("claude: {e}")))?;
+            (r, "claude".to_string())
+        }
         other => {
             return Err((
                 StatusCode::BAD_REQUEST,
-                format!("unknown provider '{other}' — supported: ollama, ollama_cloud, openrouter"),
+                format!("unknown provider '{other}' — supported: ollama, ollama_cloud, openrouter, gemini, claude"),
             ));
         }
     };