fix(monitor): use exact session ID for control agent continuation (OpenCode and Claude)

[proboscis]

Problem

When orch-monitor tries to reuse a previous control agent session, it uses generic continuation flags instead of explicit session IDs:

• OpenCode: Uses --continue instead of --session <session_id>
• Claude: May use --continue instead of --session-id <session_id>

This causes another running session to be attached as the control agent in orch-monitor, instead of the intended session.

Expected Behavior

orch-monitor should always use explicit session ID flags to resume the exact control agent session:

• OpenCode: opencode --session <session_id>
• Claude: claude --session-id <session_id>

Current Behavior

Uses --continue which attaches to whatever session the agent considers "most recent", which may be a different running session.

Fix

Ensure all control agent continuation commands use explicit session IDs:

# OpenCode - change from:
opencode --continue ...
# to:
opencode --session <session_id> ...

# Claude - change from:
claude --continue ...
# to:
claude --session-id <session_id> ...

This ensures the correct control agent session is resumed regardless of other running sessions.

Files to Check

• orch-monitor-tui/orch_monitor/__main__.py - control agent launch logic
• Any other files that launch or continue agent sessions for the monitor