Add game_complete event logging to connections

[matsonj]

Add a game_complete (or puzzle_complete) controllog event at the end of each connections puzzle for leaderboards and analytics.

Context

ChainLex now emits a game_complete event with payload:

• game_id
• model info
• outcome (win/loss)
• scores
• correct guesses
• wall_ms (duration)
• cost tracking

Task

Adapt this pattern for connections with relevant fields:

• puzzle_id
• model
• outcome (solved/failed)
• categories_found (0-4)
• strikes (0-4)
• guesses made
• difficulty breakdown (which categories solved)
• duration
• costs

This enables building leaderboards, puzzle difficulty analysis, and efficiency metrics from controllog.