# Handoff Report: Unit Test Design & Remediation Verification for Milestone M2

- **Agent**: `explorer_m2_progression_3_gen2`
- **Role**: Teamwork Preview Explorer / Synthesizer
- **Working Directory**: `c:\Projects\FreeExile\.agents\teamwork\explorer_m2_progression_3_gen2`
- **Recipient**: `orchestrator_4` (`6f4a2aa2-4315-4660-8cb7-8352a7220c95`)
- **Date**: 2026-10-01T03:13:00Z
- **Type**: Hard Handoff

---

## 1. Observation

1. **Test Suite Baselines**:
   - `pytest tests/unit/test_level_progression_service.py -v`: 33 passed in 0.19s.
   - `pytest tests/e2e/test_level_progression_e2e.py -v`: 47 passed, 3 xfailed in 0.37s. (The 3 xfailed tests are `test_f06_trial_10_rejected_at_level_99`, `test_f06_trial_10_accepted_at_level_100`, and `test_f07_godhood_keystone_metamorphosis_flag`, explicitly scoped to Milestone M3).
   - `python tools/lint/check_code_and_doc_hygiene.py --strict`: Passed 100% on hard cap rules.

2. **Level 100 Cumulative EXP Overflow**:
   - Observed in `server/world/level_progression_service.py:253`:
     ```python
     cumulative_exp=player.cumulative_exp + exp_awarded,
     ```
   - Running command:
     ```powershell
     python -c "from server.world.level_progression_service import LevelProgressionService; s = LevelProgressionService(); s.set_player_state('t', level=99, current_exp=s.get_delta_exp(99) - 1); res = s.award_monster_exp('t', 100, 100, 1000000); info = s.get_level_info('t'); b100 = s.get_benchmark(100); print('diff:', info.cumulative_exp - b100.cumulative_exp)"
     ```
   - Verbatim Output: `diff: 999999`. Level 100 cumulative EXP reached 24,286,477,314 instead of the benchmark cap 24,285,477,315.

3. **Level 100 Death Handling Early Return**:
   - Observed in `server/world/level_progression_service.py:298-300`:
     ```python
     player = self.get_player_state(player_id)
     if player.level >= 100:
         return self._build_death_result(player, 0, 0.0, player.current_exp)
     ```
   - Running command:
     ```powershell
     python -c "from server.world.level_progression_service import LevelProgressionService; s = LevelProgressionService(); p = s.set_player_state('t', level=100); events = []; s.add_death_penalty_listener(lambda r: events.append(r)); s.apply_death_penalty('t'); print('deaths:', s.get_level_info('t').deaths_count, 'events:', len(events))"
     ```
   - Verbatim Output: `deaths: 0 events: 0`. Both `deaths_count` incrementation and listener event dispatch were dropped.

4. **Corpse Overkill & Callback Invocation**:
   - Observed in `server/world/combat_engine.py:174-176, 188-190`:
     ```python
     defender.current_hp = max(0.0, defender.current_hp - final_damage)
     is_fatal = (defender.current_hp <= 0.0)
     ...
     if is_fatal and self.on_fatal_damage is not None:
         self.on_fatal_damage(result, attacker, defender)
     ```
   - When striking a defender with `current_hp == 0.0`, `is_fatal` remained `True`, triggering duplicate callbacks.
   - Running `python .agents/teamwork/challenger_m2_progression_2/challenge_combat_progression.py`:
     - Verbatim findings:
       `ADVERSARIAL_OBSERVATION: Striking an already-dead actor (current_hp == 0.0) re-evaluates is_fatal=True because current_hp <= 0.0 condition is met again.`
       `VULNERABILITY [HIGH/CRITICAL]: Corpse Multi-Hit EXP Duplication! Striking dead goblin (HP=0) awarded additional 25 EXP`
       `VULNERABILITY [HIGH]: Multi-Hit Channeled Death Penalty Drain! Player struck 3 times by same barrage suffered 3 deaths, losing 45% EXP instead of 15%`
     - Challenger Verdict: `REQUEST_CHANGES` (Exit code 1).

5. **Empirical Challenge Verification with In-Memory Remediation Patches**:
   - Applying `was_alive = (defender.current_hp > 0.0)` in `combat_engine.py`, removing line 298-299 in `level_progression_service.py`, clamping `new_cum_exp` at level 100, and sanitizing `raw_exp = max(0, raw_exp)`:
   - Verbatim output:
     `CHALLENGE SUITE RESULTS: all 6 PASSED`
     `CHALLENGER VERDICT: APPROVE`
     `OVERALL SUCCESS: True` (Exit code 0).
     `PYTEST: 80 passed, 3 xfailed in 0.49s` (Exit code 0).

---

## 2. Logic Chain

1. **From Observation 2 to Remediation 1**:
   The requirement dictates that Level 100 cumulative EXP must cap strictly at $24,285,477,315$. Because `_apply_exp_gain` unconditionally added `exp_awarded` to `cumulative_exp`, surplus EXP leaked past the terminal level. Therefore, when `curr_lvl >= 100`, `cumulative_exp` must be clamped to `b100.cumulative_exp`.

2. **From Observation 3 to Remediation 2**:
   Removing lines 298-299 allows `apply_death_penalty()` to run through the standard state update logic. Because `get_death_penalty_ratio(100)` returns `0.0` and `get_delta_exp(100)` returns `0`, `exp_lost` evaluates to `0`, `current_exp` remains `0`, `de_leveled` is `False`, `deaths_count` increments from $0 \rightarrow 1$, and all registered `_death_listeners` receive the `DeathPenaltyResult`.

3. **From Observation 4 to Remediation 3**:
   A fatal event is semantically an active transition from life to death. By tracking `was_alive = defender.current_hp > 0.0` and evaluating `is_fatal = was_alive and (defender.current_hp <= 0.0)`, strikes on dead actors yield `is_fatal == False`. This eliminates corpse EXP duplication and prevents multi-hit death penalty drain on dying players.

4. **From Observation 5 to Test Case Formulation**:
   The 9 designed unit test cases directly target each edge condition, providing a regression shield for the implementation while ensuring 100% compatibility with existing unit tests, E2E tests, and the empirical challenge suite.

---

## 3. Caveats

- **Scope Boundary**: As verified in Observation 1, the 3 xfailed tests in `tests/e2e/test_level_progression_e2e.py` belong to Milestone M3 (`AscendancyEngine` Trial 10 gating and `GODHOOD_AVATAR_METAMORPHOSIS` keystone) and must remain untouched in M2.
- **Read-Only Explorer Constraint**: No production files (`level_progression_service.py`, `combat_engine.py`, `test_level_progression_service.py`) were modified by this explorer agent. All code changes and test cases are delivered via `report.md` and this handoff.

---

## 4. Conclusion

All 4 remediation targets have been thoroughly analyzed, traced to exact source lines, empirically validated, and formalized into complete unit test specifications:

1. **Target 1**: Level 100 cumulative EXP clamping test cases designed (`test_level_100_cumulative_exp_clamping_on_level_up`, `test_level_100_set_player_state_cumulative_exp_clamping`, `test_level_100_further_monster_kills_maintain_cumulative_exp_cap`).
2. **Target 2**: Level 100 death handling test cases designed (`test_level_100_death_handling_telemetry_and_listener`, `test_level_100_consecutive_death_streak_increments_deaths_count`).
3. **Target 3**: Corpse overkill test cases designed (`test_combat_corpse_overkill_produces_not_fatal_and_no_callback`, `test_combat_corpse_overkill_does_not_duplicate_monster_exp`, `test_combat_channeled_barrage_on_dead_player_does_not_multiply_death_penalty`).
4. **Target 4**: Input sanitization test case designed (`test_award_monster_exp_negative_base_exp_sanitized_to_zero`).

Full implementation diffs and ready-to-paste Python test code are available in `c:\Projects\FreeExile\.agents\teamwork\explorer_m2_progression_3_gen2\report.md`.

---

## 5. Verification Method

To verify the test suite and fixes once applied:

1. **Run Unit Test Suite**:
   ```powershell
   pytest tests/unit/test_level_progression_service.py -v
   ```
   *Expected*: All 42 unit tests PASS (33 existing + 9 new).

2. **Run E2E Test Suite**:
   ```powershell
   pytest tests/e2e/test_level_progression_e2e.py -v
   ```
   *Expected*: 47 passed, 3 xfailed (Exit code 0).

3. **Run Challenge Suite**:
   ```powershell
   python .agents/teamwork/challenger_m2_progression_2/challenge_combat_progression.py
   ```
   *Expected*: `CHALLENGER VERDICT: APPROVE`, 0 vulnerabilities detected (Exit code 0).

4. **Run Static Analysis & Hygiene Gate**:
   ```powershell
   python -m mypy --explicit-package-bases --follow-imports=silent server/world/level_progression_types.py server/world/level_progression_service.py server/world/combat_engine.py tests/unit/test_level_progression_service.py
   python tools/lint/check_code_and_doc_hygiene.py --strict
   ```
   *Expected*: Mypy success (0 errors) and hygiene pass (0 hard cap violations).