docs: restructure README with i18n, static diagrams, and accuracy fixes

Restructure:
- Reduce README from ~950 to ~280 lines (hub-and-spoke pattern)
- Move Project Status to CHANGELOG.md
- Add hero section: centered title, tagline, description, badges
- Add nav links: Documentation, Quick Start, Twitter/X (OpenFang pattern)
- Add Documentation table linking all docs.goclaw.sh sections
- Replace 3 mermaid diagrams with static images for consistent rendering

Accuracy fixes:
- Fix provider count: 13+ → 20+ (verified from gateway_providers.go)
- Fix "5-layer defense" → 5-layer permission system per policy.go
- Add missing features: Heartbeat, Scheduling/Cron, Observability
- Fix all docs URLs to docs.goclaw.sh hash routing
- Add VPS $5 minimum 2GB RAM note for Docker

Internationalization (30 languages, ZeroClaw coverage):
zh-CN, ja, ko, vi, tl, es, pt, it, de, fr, ar, hi, ru, bn, he,
pl, cs, nl, tr, uk, id, th, ur, ro, sv, el, hu, fi, da, nb
- Keep product feature names in English: Extended Thinking, Heartbeat
- Vietnamese README hand-tuned for natural phrasing

Author: thieung

CHANGELOG.md

@@ -0,0 +1,49 @@
+# Changelog
+
+All notable changes to GoClaw are documented here. For full documentation, see [docs.goclaw.sh](https://docs.goclaw.sh).
+
+## Project Status
+
+### Implemented & Tested in Production
+
+- **Agent management & configuration** — Create, update, delete agents via API and web dashboard. Agent types (`open` / `predefined`), agent routing, and lazy resolution all tested.
+- **Telegram channel** — Full integration tested: message handling, streaming responses, rich formatting (HTML, tables, code blocks), reactions, media, chunked long messages.
+- **Seed data & bootstrapping** — Auto-onboard, DB seeding, migration pipeline tested end-to-end.
+- **User-scope & content files** — Per-user context files (`user_context_files`), agent-level context files (`agent_context_files`), virtual FS interceptors, per-user seeding (`SeedUserFiles`), and user-agent profile tracking all implemented and tested.
+- **Core built-in tools** — File system tools (`read_file`, `write_file`, `edit_file`, `list_files`, `search`, `glob`), shell execution (`exec`), web tools (`web_search`, `web_fetch`), and session management tools tested in real agent loops.
+- **Memory system** — Long-term memory with pgvector hybrid search (FTS + vector) implemented and tested with real conversations.
+- **Agent loop** — Think-act-observe cycle, tool use, session history, auto-summarization, and subagent spawning tested in production.
+- **WebSocket RPC protocol (v3)** — Connect handshake, chat streaming, event push all tested with web dashboard and integration tests.
+- **Store layer (PostgreSQL)** — All PG stores (sessions, agents, providers, skills, cron, pairing, tracing, memory, teams) implemented and running.
+- **Browser automation** — Rod/CDP integration for headless Chrome, tested in production agent workflows.
+- **Lane-based scheduler** — Main/subagent/team/cron lane isolation with concurrent execution tested. Group chats support up to 3 concurrent agent runs per session with adaptive throttle and deferred session writes for history isolation.
+- **Security hardening** — Rate limiting, prompt injection detection, CORS, shell deny patterns, SSRF protection, credential scrubbing all implemented and verified.
+- **Web dashboard** — Channel management, agent management, pairing approval, traces & spans viewer, skills, MCP, cron, sessions, teams, and config pages all implemented and working.
+- **Prompt caching** — Anthropic (explicit `cache_control`), OpenAI/MiniMax/OpenRouter (automatic). Cache metrics tracked in trace spans and displayed in web dashboard.
+- **Agent delegation** — Inter-agent task delegation with permission links, sync/async modes, per-user restrictions, concurrency limits, and hybrid agent search. Tested in production.
+- **Agent teams** — Team creation with lead/member roles, shared task board (create, claim, complete, search, blocked_by dependencies), team mailbox (send, broadcast, read). Tested in production.
+- **Evaluate loop** — Generator-evaluator feedback cycles with configurable max rounds and pass criteria. Tested in production.
+- **Delegation history** — Queryable audit trail of inter-agent delegations. Tested in production.
+- **Skill system** — BM25 search, ZIP upload, SKILL.md parsing, and embedding hybrid search. Tested in production.
+- **MCP integration** — stdio, SSE, and streamable-http transports with per-agent/per-user grants. Tested in production.
+- **Cron scheduling** — `at`, `every`, and cron expression scheduling. Tested in production.
+- **Docker sandbox** — Isolated code execution in containers. Tested in production.
+- **Text-to-Speech** — OpenAI, ElevenLabs, Edge, MiniMax providers. Tested in production.
+- **HTTP API** — `/v1/chat/completions`, `/v1/agents`, `/v1/skills`, etc. Tested in production. Interactive Swagger UI at `/docs`.
+- **API key management** — Multi-key auth with RBAC scopes, SHA-256 hashed storage, show-once pattern, optional expiry, revocation. HTTP + WebSocket CRUD. Web UI for management.
+- **Hooks system** — Event-driven hooks with command evaluators (shell exit code) and agent evaluators (delegate to reviewer). Blocking gates with auto-retry and recursion-safe evaluation.
+- **Media tools** — `create_image` (DashScope, MiniMax), `create_audio` (OpenAI, ElevenLabs, MiniMax, Suno), `create_video` (MiniMax, Veo), `read_document` (Gemini File API), `read_image`, `read_audio`, `read_video`. Persistent media storage with lazy-loaded MediaRef.
+- **Additional provider modes** — Claude CLI (Anthropic via stdio + MCP bridge), Codex (OpenAI gpt-5.3-codex via OAuth).
+- **Knowledge graph** — LLM-powered entity extraction, graph traversal, force-directed visualization, and `knowledge_graph_search` agent tool.
+- **Memory management** — Admin dashboard for memory documents (CRUD, semantic search, chunk/embedding details, bulk re-indexing).
+- **Persistent pending messages** — Channel messages persisted to PostgreSQL with auto-compaction (LLM summarization) and monitoring dashboard.
+- **Heartbeat system** — Periodic agent check-ins via HEARTBEAT.md checklists with suppress-on-OK, active hours, retry logic, and channel delivery.
+
+### Implemented but Not Fully Tested
+
+- **Slack** — Channel integration implemented, not yet validated with real users.
+- **Other messaging channels** — Discord, Zalo OA, Zalo Personal, Feishu/Lark, WhatsApp channel adapters are implemented but have not been tested end-to-end in production. Only Telegram has been validated with real users.
+- **OpenTelemetry export** — OTLP gRPC/HTTP exporter implemented (build-tag gated). In-app tracing works; external OTel export not validated in production.
+- **Tailscale integration** — tsnet listener implemented (build-tag gated). Not tested in a real deployment.
+- **Redis cache** — Optional distributed cache backend (build-tag gated). Not tested in production.
+- **Browser pairing** — Pairing code flow implemented with CLI and web UI approval. Basic flow tested but not validated at scale.