Release v0.9.0: shareable HTML replays and postmortem analysis

New commands:
  agent-strace share <session-id>      — self-contained HTML replay
  agent-strace postmortem <session-id> — structured failure analysis

share: generates a fully self-contained HTML file (no CDN, no external
URLs). Includes sticky search bar with live text filtering and per-type
filter chips, collapsible phase timeline, event stream with type badges,
cost breakdown table, and dark-theme responsive layout.

postmortem: detects root cause (first ERROR or tool failure), builds
causal timeline with retry flagging, calculates wasted time/cost,
detects AGENTS.md violations, and generates recommendations.

Zero new dependencies. 33 new tests.

Co-authored-by: Ona <no-reply@ona.com>

Author: Siddhant-K-code

src/agent_trace/__init__.py

@@ -1,3 +1,3 @@
 """agent-trace: strace for AI agents."""
 
-__version__ = "0.8.0"
+__version__ = "0.9.0"