Record a per-tick timeline in the trace #48

Problem

The editor and the user need a Workshop-Inspector-like view of a run: which rules ran at which server frame, how variables changed, what was logged. The trace only has end-of-run state (logs, globals, players, hud), so nothing can be shown per frame.

Scope

• Add a timeline to Trace: one entry per tick that had activity (empty ticks omitted), in order. Each entry holds: tick, time (ms), the rule executions started or resumed on that tick (rule index and name, eventPlayer id or null, how it ended: finished, waiting with wake tick, aborted), and the state changes in execution order: global and player variable writes (name, index path when an array element, old, new), world-state changes (health/cooldown/ultimate), HUD element creation/destruction, log lines.
• Bound the size: cap on entries with a truncated marker, so a long Bastion run cannot blow up the JSON. Pick and document the cap.
• Recording is part of the simulator; wasm32 build stays green. Existing fields keep their meaning. A run that ends not_modeled still returns the timeline up to the stop.
• Document the JSON shape in docs/simulator-interface.md. Add the shape to docs/scenario.schema.json only if the schema covers traces.

Acceptance criteria

• Test: a program with Set Global Variable, Wait(0.5), then a second write yields timeline entries at the expected ticks with correct old/new and a wait wake tick.
• Test: a not_modeled stop keeps the entries before the stop.
• Test: the cap truncates and sets the marker.
• Existing tests unchanged and green; standard gates and wasm32 build pass.

Non-goals

Any viewer UI (editor issue); new modeled constructs.