Migrate all quests and interfaces to native Go engines

[zoeyrose]

Outcome

Convert the complete authored quest/dialogue/interface estate to compiled definitions plus the generic Go engines, preserving existing gameplay choices while removing runtime Python.

Scope and invariants

• Close every migration-manifest row for the 16 quest XML files, 83 interface XML files, and directly related Python hooks.
• Express lifecycle, objectives, prerequisites, dialogue branches, actions, rewards, visibility, and failure behavior through Implement the native Go quest engine #43/Implement the native Go dialogue and interface engine #44/Add versioned, typed, and bounded CEL environments #45/Implement generic map/object triggers and authored action graphs #54 or a separately reviewed native Go domain handler.
• Create independently authored scenario fixtures from public behavior/design; do not mechanically translate GPL scripts/tests.
• Preserve stable IDs, progression semantics, authored text attribution/license, and cross-quest dependencies.
• Provide conversion diagnostics, semantic diffs, and a review checklist for ambiguous behavior rather than guessing.

Acceptance criteria

• Every quest/interface row is migrated, intentionally retired by an explicit product decision, or blocked by a named missing engine capability issue.
• Whole-corpus compilation/load passes; no migrated flow imports/executes Python or Starlark.
• Representative success, failure, abandon/repeat, reconnect, content-version, and reward-rollback scenarios pass.
• Client and editor consume one structured model from generated contracts/toolkit schemas.
• A final report lists preserved behavior, deliberate technical representation changes, unresolved licensing exclusions, and zero unowned rows.

Dependencies and parallelization

Depends on #43-#45, #54, whole-corpus toolkit support, and client/editor UI. Divide work by quest/dialogue domain and merge only through shared schemas.

Licensing and migration rule

Replacement Go code is MIT and independently implemented. Preserve existing gameplay/content design choices and separately licensed data; do not translate GPL runtime source or tests unless an exact contribution has a documented rights-holder MIT grant.