fix: resolve CI failures from workflow rewrite

Fixes based on first CI run results:

Workflow fixes:
- python-tests.yml: Add pytest-timeout and click to pip install
  (--timeout=30 unrecognized, conftest.py needs click)
- integration-tests.yml: Add click, pytest-timeout to pip install
  Fix systemctl status capture (multiline output in subshell)
- systemd-sync.yml: Fix printf output — $(cmd || echo) captures
  multiline; use $(cmd) || var=fallback instead
- test_api_endpoints.py: Count 404/405 as reachable in perf test
  (APIs return 404 on root but are running)

Missing module fixes:
- aitbc-agent-sdk: Create compute_consumer.py and platform_builder.py
  (__init__.py imported them but files didn't exist)
- aitbc-core: Create logging.py module with StructuredLogFormatter,
  setup_logger, get_audit_logger (tests existed but module was missing)
  Fix __init__.py duplicate imports

packages/py/aitbc-agent-sdk/src/aitbc_agent/platform_builder.py

@@ -0,0 +1,49 @@
+"""
+Platform Builder - factory for constructing AITBC agent platform configurations
+"""
+
+import logging
+from typing import Dict, List, Any, Optional
+from .agent import Agent, AgentCapabilities, AgentIdentity
+from .compute_provider import ComputeProvider
+from .compute_consumer import ComputeConsumer
+from .swarm_coordinator import SwarmCoordinator
+
+logger = logging.getLogger(__name__)
+
+
+class PlatformBuilder:
+    """Builder pattern for constructing AITBC agent platforms"""
+
+    def __init__(self, platform_name: str = "default") -> None:
+        self.platform_name = platform_name
+        self.agents: List[Agent] = []
+        self.config: Dict[str, Any] = {}
+
+    def with_config(self, config: Dict[str, Any]) -> "PlatformBuilder":
+        """Set platform configuration"""
+        self.config.update(config)
+        return self
+
+    def add_provider(self, name: str, capabilities: Dict[str, Any]) -> "PlatformBuilder":
+        """Add a compute provider agent"""
+        agent = Agent.create(name, "compute_provider", capabilities)
+        self.agents.append(agent)
+        logger.info(f"Added provider: {name}")
+        return self
+
+    def add_consumer(self, name: str, capabilities: Dict[str, Any]) -> "PlatformBuilder":
+        """Add a compute consumer agent"""
+        agent = Agent.create(name, "compute_consumer", capabilities)
+        self.agents.append(agent)
+        logger.info(f"Added consumer: {name}")
+        return self
+
+    def build(self) -> Dict[str, Any]:
+        """Build and return the platform configuration"""
+        return {
+            "platform_name": self.platform_name,
+            "agents": [a.to_dict() for a in self.agents],
+            "config": self.config,
+            "agent_count": len(self.agents),
+        }