[calebl]

Stage 5 of the dungeon plan, server half: levelling stage 1. This PR pins renderedstep/engine#97 at its head (e8a28d27cc2308e3378103194c13db57fe0973ff) and does every item in that PR's "What the server pin PR must change" list.

• A floor that says levels_up: true raises a game's level by one the first time that game stands on it. The engine heals the player to full on the same turn.
• The level belongs to the game. characters.level never moves.
• The level-up notice is written by the engine, for the player only. No model is told of it.

A world without levels_up plays exactly as before. No checked-in story world turns it on, no prompt changed, and no model was called.

What changed

1. Migration 20261031090000_add_levels_up_and_create_playthrough_floors.rb uses the engine's version and declaration exactly. db/schema.rb moves to 2026_10_31_090000. I placed the lines by hand so the existing column order stays as it was. No later migration is on origin/main (86b9764).

2. Models

   • Playthrough::FloorReached (table playthrough_floors) is written by the engine only.
     • It belongs to a playthrough, a location and an optional scene.
     • level must be in Character::LEVELS or nil, and a game has one row per floor.
     • #to_s is Game::floor_to_s word for word, and nil for a row with no level.
   • Associations: Playthrough has_many :floors_reached (destroy), Scene (nullify), Location (destroy).
   • Floor validates levels_up as a boolean.
   • The factory never rolls dice. Model tests added.

3. One game-aware reader. Playthrough#level_for(character, at: nil) and #max_hp_for(character, at: nil) mirror Game::level_at / Game::max_hp_at. Character.hit_points is the one formula. Every reader of a maximum on a game now asks the game:

   • Playthrough::Vitals: .instantiate!, Condition.for, and #max, so the hp_within_the_stat_block validation uses it too;
   • Playthrough::Turn#mend!, the cap;
   • Blow#condition and Toll#condition, at their story_timestamp;
   • Mechanics::State#sheet, which prints the game's level, as the engine's glance does.

   Character#advance! is still never called, and its comment now says why: it writes the world, and a level belongs to the game.

4. Story::Doctor#hp_above_maximum and Story::Repair#repair_hp_above_maximum now read row.playthrough.max_hp_for(row.character), and the finding's words name the game's level.

   • Test: a game raised to level 5 at 28 hp is neither reported nor clamped. One at 29 is reported and clamped to 28, not 18.

5. Loader. floor: gains levels_up.

   • Anything but true or false is refused (test with "yes").
   • It is written in both directions on every load, and an absent key writes false (test).

6. Exporter. Writes levels_up: true when it is set. Round-trip test.

7. Protocol. Protocol::V1#entry appends this game's claimed floor rows that raised a level, after its tolls. The browser log (turns/_turn) shows the same notice after the tolls.

   • turn_log preloads what both read, so the "preloaded log reads no more rows" test still holds.
   • openapi.json does not describe what a notice is, so it is unchanged.
   • Test: a scene claiming a levelling row, a non-levelling row and another game's row.

8. Copies of a game. Playthrough::SqlitePackage::PLAYTHROUGH_TABLES gains playthrough_floors (test).

   • Location::OneRoomFold::REFERENCES gains playthrough_floors.location_id, which its schema-walking test requires.

9. New doctor finding floor_reached_that_is_no_floor (warning/manual, never repaired): a game's row for a place that has no floors row. Test: the game keeps its level after a repair.

10. Sweep

    • World three-floors-that-raise-you and script a-floor-raises-a-level-once are copied from the engine PR body, with their comments and why: notes.
    • The golden is vendored, and test/engine_parity/a-floor-raises-a-level-once.checks.json is written. The doctor finds no hp_above_maximum after the walk.
    • Records files are not vendored here, and test/ruby_loop_coverage.yml lists no scripts, so neither changes.
    • bin/rails engine:vectors re-exports with no change.

11. Pin: ext/renderedstep/Cargo.toml and Cargo.lock now point at e8a28d2.

Gates (both provider keys unset)

• bin/rails test: 5466 runs, 0 failures, 0 errors. This includes the game sweep.
• bin/rails engine:rust_gates: PASSED, 110 scripts: goldens, invariants, doctor and audit.
• bin/rails engine:vendored: VENDORED, byte for byte against e8a28d2.
• bin/rails engine:kept_requests: the engine reproduces every golden vector and kept request.
• bundle exec rubocop: no offenses. bin/rails zeitwerk:check: all good. bin/brakeman: no warnings.

Follow-up on the engine side

The engine PR asks for parity/worlds/three-floors-that-raise-you.sql to be rebuilt from this branch's loader. That file lives in the engine repository and is not changed here.

I built it following parity/README.md, in a scratch copy of this commit: db:schema:load, then the load_world.rb runner. Its rows are identical to the engine PR's dump. The differences are:

• table order (schema load against migrate);
• schema_sha1;
• a pinned sqlite_sequence row for playthrough_floors.

After engine#97 merges, this PR re-pins to the merge commit.