Bug Report

Platform

• Pi coding agent (Windows)
• context-mode v1.0.129

Problem

When spawning subagents via Pi's subagent() tool (parallel mode), each child agent tries to load the context-mode extension. The extension's db-lock.js (acquireDbLock) detects the parent process's PID lockfile and throws DatabaseLockedError:

Failed to load extension "context-mode/build/adapters/pi/extension.js": 
Another context-mode server is already running (PID: 4524). Stop it before starting a new instance.

This makes all subagents fail immediately — they cannot even start.

Root Cause

db-lock.js enforces single-writer via a PID-based lockfile (<dbPath>.lock). This is correct for standalone instances but breaks when:

1. Parent agent starts context-mode (holds the lock)
2. Parent spawns child subagents that inherit the same extension config
3. Each child tries to acquire the same lock → DatabaseLockedError

Current Workaround

Create a custom agent with extensions: "" (empty) to skip context-mode entirely:

subagent({ action: "create", config: { name: "ida-decompiler", extensions: "", ... } })

This works but means child agents lose all context-mode benefits (ctx_execute, ctx_search, etc.)

Proposed Fix Options

1. Read-only mode for child processes: Detect that the lock is held by the parent process and open SQLite in read-only mode instead of throwing
2. Per-process temp DB: Child agents already use tmpdir-based DBs (which isUnderTmpdir skips) — but the shared project DB path triggers the lock
3. Graceful skip: If extension loads in a subagent context (detect via env var or Pi API), skip DB initialization entirely rather than crashing
4. Share the lock: Allow child processes to share the parent's DB connection via IPC instead of opening their own

Reproduction

1. Start Pi with context-mode extension enabled
2. Run subagent({ tasks: [{ agent: "delegate", task: "hello" }, { agent: "delegate", task: "world" }], concurrency: 2 })
3. Both subagents fail with DatabaseLockedError

Related: #233 (ctx_commands injection in subagent sessions)