feat: v3.0.0 — OCP CLI, plan usage monitoring, runtime settings, prompt guard

Major release: complete management interface for the Claude proxy.

- /ocp CLI with 10 subcommands (usage, status, health, settings, logs, models, sessions, clear, restart)
- Gateway plugin for /ocp as native Telegram/Discord slash command
- Plan usage monitoring via Anthropic API rate-limit headers (session %, weekly %, reset times)
- Per-model request stats (count, avg/max elapsed, avg/max prompt chars)
- Runtime settings via PATCH /settings (tune timeouts, concurrency, prompt limits without restart)
- Prompt truncation guard at 150K chars to prevent conversation history blowup
- Circuit breaker removed — caused cascading failures in CLI-proxy architecture
- Timeout increases: Opus 150s, Sonnet 120s, Haiku 45s base first-byte
- New endpoints: /usage, /status, /settings, /logs
- README fully rewritten with CLI examples and changelog

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

ocp-plugin/openclaw.plugin.json

@@ -0,0 +1,17 @@
+{
+  "id": "ocp",
+  "name": "OCP Commands",
+  "description": "Slash commands for the OpenClaw Proxy — /ocp usage, /ocp settings, /ocp health, etc.",
+  "version": "1.0.0",
+  "configSchema": {
+    "type": "object",
+    "additionalProperties": false,
+    "properties": {
+      "proxyUrl": {
+        "type": "string",
+        "default": "http://127.0.0.1:3456",
+        "description": "URL of the Claude proxy"
+      }
+    }
+  }
+}