fix(cli): send api-keys via X-API-Key in client.New + help surface

passmgr.GetToken returns an api-key in padded-cell mode (provisioned by
scripts/provision-hf-accounts.sh via 'hf user reset-apikey'), but every
call site funneled that through client.New which sent it as a
'Authorization: Bearer <hex>'. The HF backend's HTTPBearer middleware
expects JWT shape there and rejects hex strings as 'Could not validate
credentials'. The d2b83ad backend fix added a Bearer-fallback that tries
the value as an api-key, which masked the issue against current prod;
older backends or any future change in that fallback still 401.

Two changes:
- client.New auto-detects shape: 'eyJ'-prefix + two dots == JWT (Bearer),
  anything else == api-key (X-API-Key). Empty token sets neither header.
- internal/help/surface.go's loadPermissionState (called by hf --help
  introspection) switches to client.NewWithAPIKey explicitly so the
  command-discovery path doesn't depend on the heuristic at all. When
  that path failed silently (Known:false), agents would see only the
  always-permitted commands ('user.*', 'agent.status', 'config',
  'health', 'version') and conclude they had no project permission.

Adds internal/client/client_test.go covering both header paths plus
empty-token, isLikelyJWT cases, and NewWithAPIKey precedence.

Verified end-to-end in sim against a rebuilt hf-backend matching prod
(commit d2b83ad): cli with --token <api-key> sends X-Api-Key header,
backend returns 200 on /projects + /auth/me/permissions.

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

internal/client/client.go

@@ -19,14 +19,34 @@ type Client struct {
 }
 
 // New creates a Client with the given base URL and optional auth token.
+//
+// The token is sent as Authorization: Bearer when it looks like a JWT
+// (eyJ-prefixed, three dot-separated segments). Anything else is treated as
+// an API key and sent via X-API-Key. This lets call sites that historically
+// passed an api-key as a "token" (e.g. the value returned by passmgr.GetToken
+// in padded-cell mode) authenticate correctly without per-callsite churn.
 func New(baseURL, token string) *Client {
-	return &Client{
+	c := &Client{
 		BaseURL: strings.TrimRight(baseURL, "/"),
-		Token:   token,
 		HTTPClient: &http.Client{
 			Timeout: 30 * time.Second,
 		},
 	}
+	if isLikelyJWT(token) {
+		c.Token = token
+	} else if token != "" {
+		c.APIKey = token
+	}
+	return c
+}
+
+// isLikelyJWT returns true for tokens that look like a JSON Web Token:
+// "eyJ"-prefixed (base64-encoded JSON header opening with `{"`) and exactly
+// two dots separating header.payload.signature. API keys minted by the HF
+// backend are hex (`/users/{id}/apikey` returns a 64-hex-char `key`); fabric
+// keys use a `fak_` prefix. None of those match this shape.
+func isLikelyJWT(token string) bool {
+	return strings.HasPrefix(token, "eyJ") && strings.Count(token, ".") == 2
 }
 
 // NewWithAPIKey creates a Client that authenticates using X-API-Key.