Fuzzy completion: SHOW PLAN NODE node ID completion

[apstndb]

Summary

Add fuzzy completion for SHOW PLAN NODE <node_id> to select from nodes in the last cached query plan.

Background

SHOW PLAN NODE requires knowing the exact node ID from the last query plan. The node list is already available in memory from the preceding query or EXPLAIN ANALYZE.

Design

• New completion type: fuzzyCompletePlanNode
• Data source: in-memory cached query plan nodes (no network call needed)
• Uses fzfItem{Value, Label} (Fuzzy finder: introduce fzfItem for display/insert text separation #525) for display/insert separation:
  • Value (inserted): node ID
  • Label (displayed/searched): node ID with operator type / display name
• No caching needed — data is already in memory

Acceptance Criteria

• After running a query or EXPLAIN ANALYZE, SHOW PLAN NODE + Ctrl+T shows available nodes
• Each node displays its ID and operator name for easy selection
• Graceful handling when no plan is cached

Prerequisites

• Fuzzy finder: introduce fzfItem for display/insert text separation #525 (fzfItem display/insert separation)

Related

• Fuzzy completion: remaining tasks #509 (origin tracking issue)