[Bug] oclite: Session resets after every message — agent loses conversation context

[randomm]

Bug

After every message, currentSessionID is set to null in the finally blocks of both handleMessage() and handleCustomCommand(). This causes each user message to create a brand new session with zero conversation history.

Reproduction

1. Send a message: "Is issue 184 still open?"
2. Agent responds correctly about Can't continue session after closing opencode while working anomalyco/opencode#184
3. Send follow-up: "Is there a PR linked to it?"
4. Agent responds: "I don't have context for what 'it' refers to"

Root Cause

File: packages/opencode/src/cli/lite/index.ts

Line ~540 (handleMessage finally block):

finally {
  isOperationInProgress = false
  currentSessionID = null  // ← BUG
}

Line ~455 (handleCustomCommand finally block):

finally {
  isOperationInProgress = false
  currentSessionID = null  // ← SAME BUG
}

Evidence

• Token count drops from 51.7k to 25.8k between messages (no history loaded)
• Session.createNext() is called every message instead of reusing the session
• MessageV2.filterCompacted(MessageV2.stream(sessionID)) returns empty history for new sessions

Fix

Delete both currentSessionID = null lines. The session ID should persist across the REPL loop. It's already properly reset when the user runs /new (line ~275).

Acceptance Criteria

• Conversation context preserved across multiple messages
• /new command still creates a fresh session
• bun run typecheck passes
• bun test passes

[randomm]

Fixed in commit 1a20287. Removed two currentSessionID = null lines from finally blocks. Adversarial review approved — race condition mitigated by existing isOperationInProgress guard.