fix(authz): une seule regle pour l'acces coach vers joueur

SEC-AUTHZ-004 et SEC-AUTHZ-005. La meme question -- ce coach peut-il agir
sur ce joueur ? -- recevait cinq reponses differentes selon la route :

  teams.py:add_player_note     verifiait l'appartenance via TeamPlayer
  users.py, 4 routes de notes  ne verifiaient rien au-dela d'isinstance
  contract.py:can_view         interrogeait la colonne heritee coach_id, et
                               traitait un team_id nul comme un joker

Consequences levees
  - tout coach pouvait ecrire une note nominative sur tout joueur du club.
    Ces notes sont visibles par le joueur concerne.
  - tout coach figurant dans OrgTeam.coach_id pouvait lire n'importe quel
    contrat sans equipe rattachee. Or upload_contract laisse team_id nul des
    que le joueur n'appartient a aucune equipe : la condition
    `not self.team_id or ...` ouvrait donc largement.
  - symetriquement, un coach rattache uniquement par la relation
    many-to-many ne voyait aucun contrat.

app/permissions.py
  Premier pas concret vers ARCH-002, sans refonte : un module unique, pas
  une couche de services. coach_org_team_ids() lit la relation m2m ET la
  colonne heritee, donc le deuxieme coach d'une equipe cesse d'etre
  invisible. coach_can_access_player() accorde l'acces si le joueur est sur
  une equipe du coach, ou inscrit a un tryout qu'il gere, ou participant a
  un match de ce tryout.

14 tests, dont deux verifient que les chemins legitimes fonctionnent
toujours : un coach note bien son propre joueur, et voit bien son contrat.

Note : la regle metier retenue -- equipe OU tryout -- est une lecture du
comportement existant, pas une decision produit. Si le club attend autre
chose, c'est desormais un seul endroit a changer.

Co-Authored-By: Claude Opus 5 <[email protected]>

tests/test_permissions.py

@@ -0,0 +1,238 @@
+"""Coach ↔ player access rules.
+
+SEC-AUTHZ-004 and SEC-AUTHZ-005. The same question — "may this coach act on
+this player?" — was answered five different ways across the codebase:
+
+    teams.py:add_player_note        checked TeamPlayer membership
+    users.py, four note routes      checked nothing beyond isinstance(Coach)
+    contract.py:can_view            checked the legacy coach_id column, and
+                                    treated a null team_id as a wildcard
+
+app/permissions.py now holds one rule, and it reads both the many-to-many
+relationship and the legacy column — so the second coach of a team is no
+longer invisible to it (ARCH-002).
+"""
+
+from datetime import date
+
+import pytest
+
+from app.extensions import db
+from app.models import (
+    Contract, OrgTeam, PersonalNote, TeamPlayer, Tryout, TryoutRegistration,
+)
+from app.permissions import coach_can_access_player, coach_org_team_ids
+
+
+@pytest.fixture
+def team_factory(app):
+    def _make(name, *, coach_id=None, legacy_coach_id=None, player_ids=()):
+        with app.app_context():
+            from app.models import User
+
+            team = OrgTeam(name=name, created_by=coach_id or legacy_coach_id,
+                           coach_id=legacy_coach_id)
+            db.session.add(team)
+            db.session.flush()
+            if coach_id:
+                team.coaches.append(db.session.get(User, coach_id))
+            for player_id in player_ids:
+                db.session.add(TeamPlayer(player_id=player_id, org_team_id=team.id))
+            db.session.commit()
+            return team.id
+
+    return _make
+
+
+class TestTeamResolution:
+    def test_a_coach_attached_by_the_relationship_is_found(
+        self, app, make_user, team_factory
+    ):
+        coach_id = make_user('coach')
+        team_id = team_factory('Varsity', coach_id=coach_id)
+
+        with app.app_context():
+            from app.models import User
+            coach = db.session.get(User, coach_id)
+            assert coach_org_team_ids(coach) == [team_id]
+
+    def test_a_coach_attached_by_the_legacy_column_is_found(
+        self, app, make_user, team_factory
+    ):
+        coach_id = make_user('coach')
+        team_id = team_factory('JV', legacy_coach_id=coach_id)
+
+        with app.app_context():
+            from app.models import User
+            coach = db.session.get(User, coach_id)
+            assert coach_org_team_ids(coach) == [team_id]
+
+    def test_an_unattached_coach_has_no_team(self, app, make_user):
+        coach_id = make_user('coach')
+        with app.app_context():
+            from app.models import User
+            assert coach_org_team_ids(db.session.get(User, coach_id)) == []
+
+
+class TestPlayerAccess:
+    def test_a_coach_reaches_a_player_on_their_team(self, app, make_user, team_factory):
+        coach_id = make_user('coach')
+        player_id = make_user('player')
+        team_factory('Varsity', coach_id=coach_id, player_ids=[player_id])
+
+        with app.app_context():
+            from app.models import User
+            assert coach_can_access_player(db.session.get(User, coach_id), player_id)
+
+    def test_a_second_coach_of_the_team_also_reaches_the_player(
+        self, app, make_user, team_factory
+    ):
+        """The case that used to fail everywhere users.py looked at coach_id."""
+        first_coach = make_user('coach')
+        second_coach = make_user('coach')
+        player_id = make_user('player')
+        team_id = team_factory('Varsity', legacy_coach_id=first_coach,
+                               player_ids=[player_id])
+
+        with app.app_context():
+            from app.models import User
+            team = db.session.get(OrgTeam, team_id)
+            team.coaches.append(db.session.get(User, second_coach))
+            db.session.commit()
+
+            assert coach_can_access_player(db.session.get(User, second_coach), player_id)
+
+    def test_a_coach_does_not_reach_an_unrelated_player(
+        self, app, make_user, team_factory
+    ):
+        coach_id = make_user('coach')
+        stranger_id = make_user('player')
+        team_factory('Varsity', coach_id=coach_id)
+
+        with app.app_context():
+            from app.models import User
+            assert not coach_can_access_player(db.session.get(User, coach_id), stranger_id)
+
+    def test_a_coach_reaches_a_player_registered_in_their_tryout(
+        self, app, make_user
+    ):
+        coach_id = make_user('coach')
+        player_id = make_user('player')
+
+        with app.app_context():
+            from app.models import User
+            tryout = Tryout(title='Open tryout', game='Valorant',
+                            date=date(2030, 3, 1), created_by=coach_id)
+            db.session.add(tryout)
+            db.session.flush()
+            tryout.coaches.append(db.session.get(User, coach_id))
+            db.session.add(TryoutRegistration(tryout_id=tryout.id, player_id=player_id))
+            db.session.commit()
+
+            assert coach_can_access_player(db.session.get(User, coach_id), player_id)
+
+    def test_a_missing_player_id_is_refused(self, app, make_user):
+        coach_id = make_user('coach')
+        with app.app_context():
+            from app.models import User
+            assert not coach_can_access_player(db.session.get(User, coach_id), None)
+
+
+class TestPersonalNoteRoutes:
+    """SEC-AUTHZ-004 — every coach could write a nominative note about
+    every player of the club. The notes are visible to the player."""
+
+    def test_a_coach_cannot_note_an_unrelated_player(
+        self, app, client, as_role, make_user, team_factory
+    ):
+        stranger_id = make_user('player')
+        coach_id = as_role('coach')
+        team_factory('Varsity', coach_id=coach_id)
+
+        client.post('/users/personal-notes/manage', data={
+            'player_id': stranger_id, 'content': 'Unrelated observation',
+        }, follow_redirects=True)
+
+        with app.app_context():
+            assert PersonalNote.query.filter_by(player_id=stranger_id).count() == 0
+
+    def test_a_coach_can_still_note_their_own_player(
+        self, app, client, as_role, make_user, team_factory
+    ):
+        """Guard against over-correcting."""
+        player_id = make_user('player')
+        coach_id = as_role('coach')
+        team_factory('Varsity', coach_id=coach_id, player_ids=[player_id])
+
+        client.post('/users/personal-notes/manage', data={
+            'player_id': player_id, 'content': 'Good positioning today',
+        }, follow_redirects=True)
+
+        with app.app_context():
+            note = PersonalNote.query.filter_by(player_id=player_id).one()
+            assert note.content == 'Good positioning today'
+
+
+class TestContractVisibility:
+    """SEC-AUTHZ-005 — `not self.team_id` was a wildcard, and upload_contract
+    leaves team_id null whenever the player has no team."""
+
+    @staticmethod
+    def _contract(app, player_id, uploader_id, team_id=None):
+        with app.app_context():
+            contract = Contract(
+                player_id=player_id, team_id=team_id, uploaded_by_id=uploader_id,
+                original_filename='c.pdf', stored_filename='uuid.pdf',
+                file_path='/tmp/uuid.pdf',
+            )
+            db.session.add(contract)
+            db.session.commit()
+            return contract.id
+
+    def test_a_teamless_contract_is_not_visible_to_every_coach(
+        self, app, make_user, team_factory
+    ):
+        coach_id = make_user('coach')
+        stranger_id = make_user('player')
+        admin_id = make_user('admin')
+        team_factory('Varsity', legacy_coach_id=coach_id)
+        contract_id = self._contract(app, stranger_id, admin_id, team_id=None)
+
+        with app.app_context():
+            from app.models import User
+            contract = db.session.get(Contract, contract_id)
+            assert not contract.can_view(db.session.get(User, coach_id))
+
+    def test_a_coach_sees_the_contract_of_their_own_player(
+        self, app, make_user, team_factory
+    ):
+        coach_id = make_user('coach')
+        player_id = make_user('player')
+        admin_id = make_user('admin')
+        team_factory('Varsity', coach_id=coach_id, player_ids=[player_id])
+        contract_id = self._contract(app, player_id, admin_id)
+
+        with app.app_context():
+            from app.models import User
+            contract = db.session.get(Contract, contract_id)
+            assert contract.can_view(db.session.get(User, coach_id))
+
+    def test_the_player_always_sees_their_own_contract(self, app, make_user):
+        player_id = make_user('player')
+        admin_id = make_user('admin')
+        contract_id = self._contract(app, player_id, admin_id)
+
+        with app.app_context():
+            from app.models import User
+            contract = db.session.get(Contract, contract_id)
+            assert contract.can_view(db.session.get(User, player_id))
+
+    def test_an_admin_sees_every_contract(self, app, make_user):
+        player_id = make_user('player')
+        admin_id = make_user('admin')
+        contract_id = self._contract(app, player_id, admin_id)
+
+        with app.app_context():
+            from app.models import User
+            contract = db.session.get(Contract, contract_id)
+            assert contract.can_view(db.session.get(User, admin_id))