fix: v0.1.1 — MCP identity, timeouts, exit codes, URL validation

Critical:
- MCP server identifies as "webclaw-mcp" instead of "rmcp"
- Research tool poll loop capped at 200 iterations (~10 min)

CLI:
- Non-zero exit codes on errors
- Text format strips markdown table syntax

MCP server:
- URL validation on all tools
- 60s cloud API timeout, 30s local fetch timeout
- Diff cloud fallback computes actual diff
- Batch capped at 100 URLs, crawl at 500 pages
- Graceful startup failure instead of panic

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

crates/webclaw-mcp/Cargo.toml

@@ -23,3 +23,4 @@ tokio = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
 reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
+url = "2"