feat: add Confluence recent pages + Sentry error tracking (MAT-58, MAT-59)

MAT-58: Add recent_confluence_pages tool to both voice and text chat.
Shows last 5 recently modified pages so users can pick directly
instead of having to search every time.

MAT-59: Integrate sentry-sdk in all three entry points (agent.py,
bot.py, voice.py). SENTRY_DSN env var, traces at 10% sample rate.
Requires creating project in Sentry UI and setting DSN.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agent.py

@@ -3,6 +3,8 @@ import json
 import base64
 import logging
 
+import sentry_sdk
+
 from livekit.agents import Agent, AgentSession, AgentServer, JobContext, JobProcess, cli
 from livekit.plugins import openai as lk_openai, elevenlabs, silero
 import livekit.rtc as rtc
@@ -12,6 +14,12 @@ from e2ee_patch import KDF_HKDF
 logger = logging.getLogger("matrix-ai-agent")
 logging.basicConfig(level=logging.DEBUG)
 
+# Sentry error tracking
+_sentry_dsn = os.environ.get("SENTRY_DSN", "")
+if _sentry_dsn:
+    sentry_sdk.init(dsn=_sentry_dsn, traces_sample_rate=0.1, environment=os.environ.get("SENTRY_ENV", "production"))
+    logger.info("Sentry initialized for agent")
+
 LITELLM_URL = os.environ["LITELLM_BASE_URL"]
 LITELLM_KEY = os.environ.get("LITELLM_API_KEY", "not-needed")