T08 iter 6: game end and the three scoring modes; AM-1 at 100%

- GR-R09: after Round 5's End the game ends and scoring runs instead of
  the round advancing.
- GR-E01: claimed Problems sum their printed values against the
  player-count threshold (2p 5, 3-4p 7, 5-6p 9 in dataset 0.1).
- GR-E02 SHARED GROUND: shared score, Mastery reduced per Blame token
  and per Denied Problem.
- GR-E03 COMMON PROBLEM: personal score is claimed value less Blame,
  tiebroken by lower Stress then more Bonds.
- GR-E04 BONDED COALITIONS: connected components over Bonds only, so
  Rivalries do not connect and an unbonded player is a coalition of
  one; tiebroken by lower combined Stress then fewer Blame.

Ties yield every tied candidate rather than an arbitrary pick, which is
what "shared victory" in GR-E03/E04 asks for.

AM-1 rule coverage is now 58/58 (100%), 21 scenarios, 17 tests.

Caveat recorded rather than papered over: GR-E02's "successes" is not
defined in dataset 0.1. It is implemented as the count of claimed
Problems and both scoring scenarios are marked provisional, so a
ground-game ruling flips a scenario rather than the kernel.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scenarios/ground/gr-e02-shared-ground.yaml

@@ -0,0 +1,50 @@
+scenario: ground/gr-e02-shared-ground
+description: >
+  SHARED GROUND scoring after Round 5 (GR-R09, GR-E01, GR-E02): one
+  shared total against the player-count threshold, with a Mastery
+  rating reduced by each Blame token and each Denied Problem.
+covers: [GR-R09, GR-E01, GR-E02, GR-P03]
+provisional: true
+seed: 42
+setup:
+  players: 3
+  preset: standard-3p
+  patch:
+    "lead": 0
+    "round": 5
+    "mode": SharedGround
+    # 3p threshold is 7; claimed values 1+3 fall short.
+    "problems.1.claimed_by": 0
+    "problems.3.claimed_by": 1
+    "problems.2.denied": true
+    "players.2.blame_from": [0]
+commands:
+  - actor: P1
+    cmd: select_action
+    args: { action: INVESTIGATE, problem: 2 }
+  - actor: P2
+    cmd: select_action
+    args: { action: INVESTIGATE, problem: 2 }
+  - actor: P3
+    cmd: select_action
+    args: { action: INVESTIGATE, problem: 2 }
+  - actor: SYSTEM
+    cmd: reveal
+  - actor: SYSTEM
+    cmd: resolve
+  - actor: SYSTEM
+    cmd: end_round
+expect:
+  events:
+    - kind: GameEnded
+  state:
+    "outcome.total": 4
+    "outcome.threshold": 7
+    "outcome.group_success": false
+    # 2 claimed Problems, −1 Blame, −1 Denied.
+    "outcome.mastery": 0
+    "outcome.winners": []
+    # GR-R09: the game ended rather than advancing to Round 6.
+    "round": 5
+    "step": End
+  rejects: []