feat: v0.1.3 — crawl streaming, resume/cancel, MCP proxy support

Crawl:
- Real-time progress on stderr as pages complete
- --crawl-state saves progress on Ctrl+C, resumes from saved state
- Visited set + remaining frontier persisted for accurate resume

MCP server:
- Reads WEBCLAW_PROXY and WEBCLAW_PROXY_FILE env vars
- Falls back to proxies.txt in CWD (existing behavior)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -3,6 +3,18 @@
 All notable changes to webclaw are documented here.
 Format follows [Keep a Changelog](https://keepachangelog.com/).
 
+## [0.1.3] — 2026-03-25
+
+### Added
+- Crawl streaming: real-time progress on stderr as pages complete (`[2/50] OK https://... (234ms, 1523 words)`)
+- Crawl resume/cancel: `--crawl-state <path>` saves progress on Ctrl+C and resumes from where it left off
+- MCP server proxy support via `WEBCLAW_PROXY` and `WEBCLAW_PROXY_FILE` env vars
+
+### Changed
+- Crawl results now expose visited set and remaining frontier for accurate state persistence
+
+---
+
 ## [0.1.2] — 2026-03-25
 
 ### Changed