feat(auth): CLI tokens minted at /connect for containerized MCP clients

Adds a second token kind alongside Authentik OIDC access tokens for MCP
authentication. When the user visits /connect after signing into the Web
UI, the server mints an HMAC-signed JWT (kid="cli-v1") carrying their
Authentik identity in oidc_iss / oidc_sub claims. The token is shown
once in React state — never put in the URL or persisted on the client.

The MCP endpoint's bearer-token verifier dispatches by JWT `kid` header:
CLI tokens are verified locally via HS256(CLI_TOKEN_SECRET); everything
else goes through Authentik JWKS. Both paths resolve to the same
AuthenticatedClaims shape so userContextFromClaims handles them
identically.

This unblocks MCP clients running in containers where the OAuth loopback
callback isn't reachable — paste the token into Claude Code as a static
Authorization header and skip the OAuth flow entirely.

Revocation in v1 is "rotate CLI_TOKEN_SECRET to invalidate every issued
CLI token at once." Per-token revocation can come later if needed.

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

apps/web/lib/env.ts

@@ -30,6 +30,10 @@ const envSchema = z.object({
   // NextAuth
   NEXTAUTH_SECRET: z.string().min(32, "NEXTAUTH_SECRET must be at least 32 chars"),
 
+  // Signing key for CLI tokens minted at /connect. Rotate this to invalidate
+  // every issued CLI token at once.
+  CLI_TOKEN_SECRET: z.string().min(32, "CLI_TOKEN_SECRET must be at least 32 chars"),
+
   // Behavior flags
   ALLOW_INSECURE_HTTP: Bool.optional().default(false),
 });
@@ -72,6 +76,7 @@ function buildPhaseStub(): Env {
     EMBEDDING_MODEL: "Xenova/bge-small-en-v1.5",
     EMBEDDING_DIM: 384,
     NEXTAUTH_SECRET: "build-phase-secret-not-used-at-runtime-xxxxxxxx",
+    CLI_TOKEN_SECRET: "build-phase-secret-not-used-at-runtime-xxxxxxxx",
     ALLOW_INSECURE_HTTP: false,
   };
 }