Spec Kitty

Data Model — Mission-Type Single-Source + Gate Wiring

This mission adds no persistent data. The "model" here is the set of in-code contracts (return shapes, exception shapes, finding shapes) that the WPs must honor.

E-1 — Canonical mission-type accessor (doctrine layer)

Element	Shape	Notes
builtin_mission_type_ids()	tuple[str, ...]	Sorted (lexicographic). Cached (@functools.cache). Derived from MissionTypeRepository.default().ids().
frozenset convenience	frozenset[str]	Same members as the tuple; for membership/default consumers (Roster B, D base set).

Invariants:

• Exactly one filesystem scan per process (NFR-002); repeated calls return identical results.
• Importing any src/charter/* module triggers zero calls to this accessor (NFR-001).
• Loud-fails transitively: if MissionTypeRepository raises (id≠stem / invalid schema), the accessor raises.

E-2 — Roster derivations

Roster	File	Container	Extra members preserved
A CANONICAL_MISSION_TYPES	charter/mission_type_profiles.py	tuple/iterable	none
B _BUILTIN_MISSION_TYPE_IDS	charter/pack_context.py	frozenset	none
C _BUILTIN_MISSION_TYPES	migrations/m_3_2_0rc35_...py	list	none (live-read at apply())
D ALLOWED_MISSION_TYPES	charter/activations.py	set/frozenset	{any, generic} sentinels
E _MISSION_IDENTIFIER_ANSWERS	charter/synthesizer/interview_mapping.py	mapping	software_dev underscore alias

E-3 — ActionIndex / ActionIndexError

Element	Shape	Notes
ActionIndex (existing)	frozen dataclass, 7 list[str] artifact-kind fields + action	Unchanged shape.
ActionIndexError(ValueError) (new)	co-located in action_index.py	Message: index path + offending key + found type.

load_action_index decision table:

Input state	Behavior
File missing	Return ActionIndex(action=action) (silent fallback) — unchanged
File present, valid, empty content	Return empty-content ActionIndex — no raise
File present, non-mapping root	raise ActionIndexError
File present, artifact-kind field not a list (e.g. directives: "x")	raise ActionIndexError
File present, unparseable YAML (YAMLError)	raise ActionIndexError

E-4 — Doctrine-health cross-grain finding (#2666)

Element	Shape	Notes
Cross-grain check result	folded into existing DoctrineHealthReport health + a --json finding entry	On CrossGrainDoubleDeclarationError: report unhealthy, RC=1, structured finding (mission type + colliding URN). On success: healthy, no exit-code change.

E-5 — builtin_missions_root() (#2668)

Element	Shape	Notes
builtin_missions_root()	Path → src/doctrine/missions	Public module-level accessor; classmethod _default_built_in_dir delegates (or is replaced). Replaces 2 # noqa: SLF001 cross-class calls.