feat: Add --data-dir flag to ruvector mcp start

[dmoellenbeck]

Problem

ruvector mcp start hardcodes the data directory to process.cwd()/.ruvector/ and process.cwd()/ruvector.db. There is no way to configure where ruvector stores its data.

This is problematic when:

• The project directory should only contain source code, not runtime data
• Multiple projects share the same ruvector intelligence data
• Users want all application data in a centralized location (e.g., ~/.claude-coach/)
• The ruvector.db (redb) file appears in the project root alongside source files

Current behavior

getIntelPath() {
  const projectPath = path.join(process.cwd(), '.ruvector', 'intelligence.json');
  // ... fallback to ~/.ruvector/
}

• No --data-dir flag on ruvector mcp start
• No RUVECTOR_DATA_DIR environment variable
• No config option in ~/.ruvector/config.json

Current workaround

Symlinks:

ln -s ~/.claude-coach/ruvector .ruvector
ln -s ~/.claude-coach/ruvector.db ruvector.db

This works but is fragile (symlinks can break on clone, CI, etc.).

Proposed solution

Add a --data-dir flag to ruvector mcp start:

ruvector mcp start --data-dir ~/.claude-coach/ruvector

This should control where:

• intelligence.json, learning-state.json, biometric-index.json are stored
• ruvector.db (redb) is created
• Any future data files are placed

Also support environment variable

RUVECTOR_DATA_DIR=~/.claude-coach/ruvector ruvector mcp start

Resolution order (proposed)

1. --data-dir CLI flag (highest priority)
2. RUVECTOR_DATA_DIR environment variable
3. ~/.ruvector/config.json → data_dir key
4. Current behavior (.ruvector/ in cwd, fallback to ~/.ruvector/)

Context

Using ruvector as intelligence layer for a coaching application. All application data lives in ~/.claude-coach/ but ruvector scatters files across the project directory (.ruvector/, ruvector.db). This makes clean separation of code vs. data difficult.

Affected components

• bin/mcp-server.js → getIntelPath() method
• ruvector.db path resolution
• learning-state.json save/load paths