Implement generic map/object triggers and authored action graphs

[zoeyrose]

Outcome

Cover repeated map-local and object behavior with bounded compiled action definitions, leaving bespoke mechanics as explicit reviewed Go handlers.

Scope and invariants

• Define typed triggers for apply, enter/leave, message, timer, death, state change, portal, spawn, and other measured common events.
• Define a small versioned action graph over approved typed commands: condition, sequence, choice, set state, spawn/despawn, transfer, message, quest/dialog handoff, and domain-service invocation.
• Compile and statically validate references, cycles, permissions, required services, and CEL expressions; runtime never interprets legacy Python.
• Execute through Implement the transactional gameplay event and action foundation #41 with deterministic order, captured identity, recursion/fan-out/step limits, cancellation, and atomic groups.
• Provide source-aware diagnostics and structured tracing without exposing hidden state to players.

Acceptance criteria

• A corpus-driven inventory proves each action/trigger exists because multiple behaviors need it; avoid an unbounded generic scripting language.
• Fuzz/property tests cover cycles, recursion, stale entities, invalid references, partial failure, huge graphs, and event storms.
• Sam's saw/activity and one map portal/puzzle run without custom script in M3.
• Unsupported bespoke behavior receives a focused Go handler issue, not an unsafe reflection escape.
• Editor/toolkit schemas and Go runtime pass the same positive/negative fixtures.

Dependencies and parallelization

Depends on #36, #41, #44, and #45. Toolkit schema/validation and editor authoring may proceed in parallel; Starlark #60 is evaluated only after this is exercised.

Independent implementation

Implement from the preserved issue-level/product behavior and independently authored fixtures. Do not copy or mechanically translate GPL server/Python code or tests. Replacement code is MIT; consumed content and assets keep their own licenses.