chore(claude-code): bump tested/required deps to the 0.3.0 line

PyPI now ships agent-manifest 0.3.0 and agentrust-trace 0.3.0. Ran the full
signing path (capture.py report) in a clean venv on
agent-manifest==0.3.0 / agentrust-trace==0.3.0 / agentrust-trace-tests==0.2.0:
manifest validates and self-verifies, the TRACE record passes the suite at
Level 0 (8/8), and the stdlib test suite is green.

- integration.yaml tested_against: agent-manifest 0.2.0 -> 0.3.0; record the
  agentrust-trace-tests version explicitly.
- requirements.txt: raise the agent-manifest floor 0.2 -> 0.3 to match the
  tested line.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: imran-siddique

claude-code/integration.yaml

@@ -11,5 +11,6 @@ license: Apache-2.0
 tier: community
 trace_conformance_level: 0
 tested_against:
-  agent-manifest: 0.2.0
+  agent-manifest: 0.3.0
   agentrust-trace: 0.3.0
+  agentrust-trace-tests: 0.2.0

claude-code/requirements.txt

@@ -4,6 +4,6 @@
 # These are required only to generate SIGNED records (/trace, /manifest approve
 # --sign): the Agent Manifest and the TRACE Trust Record. Verified against the
 # PyPI releases below in a clean virtualenv.
-agent-manifest>=0.2
+agent-manifest>=0.3
 agentrust-trace>=0.3
 agentrust-trace-tests>=0.2