Remove opencode-rag-plugin: hangs startup without Ollama embedding backend

The RAG plugin probes a local embedding backend (Ollama on localhost:11434
by default) at init with no timeout. When Ollama isn't running, opencode
hangs after loading plugins and never starts. Dropped it from the template
and documented re-enable steps + the --pure diagnostic in the README.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -66,7 +66,7 @@ echo 'export BRAVE_API_KEY=BSA...' >> ~/.bashrc
 
 ## What's Synced
 
-- **9 Plugins** - oh-my-openagent, opencode-mem, opencode-pty, dynamic context pruning, RAG, command-inject, notify, agent-identity, tokenscope
+- **8 Plugins** - oh-my-openagent, opencode-mem, opencode-pty, dynamic context pruning, command-inject, notify, agent-identity, tokenscope
 - **32 Skills** - Coding standards, frontend/backend patterns, security review, etc.
 - **3 Agents** - explorer, reviewer, docs-researcher
 - **14 MCP Servers** - codegraph, brave-search, playwright, github, context7, exa, etc.
@@ -100,6 +100,15 @@ git pull
 **Git MCP fails?**
 - Install Python package: `pip install mcp-server-git`
 
+**opencode hangs on startup (no output)?**
+- The `opencode-rag-plugin` was removed because its startup probes a local
+  embedding backend (Ollama on `localhost:11434` by default) with no timeout —
+  if Ollama isn't running, opencode hangs after loading plugins.
+- To re-enable it, first start a backend (`ollama serve` + `ollama pull embeddinggemma`,
+  or configure an OpenAI/Cohere embedding key), then add `"opencode-rag-plugin"`
+  back to the `plugin` array in `opencode.json.template`.
+- Diagnose plugin hangs with `opencode run --pure "ok"` (runs without external plugins).
+
 ## Structure
 
 ```