fix(security): redact Fireworks AI API keys in logs

Fireworks AI is a first-class provider in hermes-agent — FIREWORKS_API_KEY
is listed in tools/environments/local.py and the provider is selectable via
the model picker (api.fireworks.ai in model_metadata, hermes_cli/models.py).

Fireworks API keys follow the format fw_<40 alphanumeric chars> and were
absent from _PREFIX_PATTERNS in agent/redact.py. The ENV-assignment and
Bearer header patterns catch FIREWORKS_API_KEY=fw_... in config output,
but a raw key in a stack trace, debug print, or tool error passed through
completely unmasked.

Four unit tests added to TestFireworksToken covering bare token masking,
env assignment, short-prefix false positive, and visible prefix in output.

agent/redact.py

@@ -106,6 +106,7 @@ _PREFIX_PATTERNS = [
     r"brv_[A-Za-z0-9]{10,}",            # ByteRover API key
     r"xai-[A-Za-z0-9]{30,}",            # xAI (Grok) API key
     r"ntn_[A-Za-z0-9]{10,}",            # Notion internal integration token
+    r"fw_[A-Za-z0-9]{30,}",             # Fireworks AI API key
 ]
 
 # ENV assignment patterns: KEY=value where KEY contains a secret-like name.

tests/agent/test_redact.py

@@ -886,3 +886,25 @@ class TestFileReadNonReusableRedaction:
         out = redact_sensitive_text(f"key: {self.SK}", force=True, file_read=True)
         assert "«redacted:sk-…»" in out
         assert self.SK not in out
+
+
+class TestFireworksToken:
+    KEY = "fw_" + "A" * 40
+
+    def test_bare_token_masked(self):
+        result = redact_sensitive_text(f"fireworks error: key {self.KEY}", force=True)
+        assert self.KEY not in result
+        assert "fw_AA" in result
+
+    def test_env_assignment_masked(self):
+        result = redact_sensitive_text(f"FIREWORKS_API_KEY={self.KEY}", force=True)
+        assert self.KEY not in result
+
+    def test_too_short_not_masked(self):
+        short = "fw_tooshort"
+        result = redact_sensitive_text(f"text {short} here", force=True)
+        assert short in result
+
+    def test_prefix_visible_in_masked_output(self):
+        result = redact_sensitive_text(self.KEY, force=True)
+        assert result.startswith("fw_AA")