Spec Kitty

Phase 1 Data Model: Pack-Path Portability & Language-Scope Authority

WP1 — OrgPackConfig (extended, not replaced)

Entity: OrgPackConfig (src/doctrine/drg/org_pack_config.py) — existing pydantic value object.

Field	Type	Change	Validation rule
local_path	Path	Validator behavior changes; field type/shape unchanged	Stored value MUST remain the literal author-written template (e.g. ${SPEC_KITTY_PACK_HOME}/org-pack, ~/.spec-kitty/pack, or a plain absolute path). No expansion happens at construction/validation time.
subdir	`Path \	None`	No change

New/changed behavior — effective_root():

• Invariant: effective_root() is the single point where local_path is expanded (os.path.expandvars then os.path.expanduser) before the existing is_absolute() classification, subdir join, and symlink-containment check run. No other code path performs expansion.
• Invariant: An unset or empty referenced variable raises a named error (extending the existing OrgPackMissingError family) identifying the missing variable name and the configured pack name. Resolution never returns a path containing a literal, unexpanded ${...} token, and never silently degrades to an empty org layer.
• Invariant: A save→load round-trip (save_pack_registry → reload) MUST preserve the literal local_path string exactly as authored. This is a property of not mutating the field at construction, not an additional check.

Legacy shape: _registry_from_legacy_organisation_packs / _build_legacy_single_pack construct the same OrgPackConfig, so they inherit the corrected behavior automatically — no parallel implementation.

WP2 — Compiled charter language set (new structured field)

Entity: Compiled charter language artefact (new).

Field	Type	Owner	Description
languages (or equivalent structured field, exact name/location TBD by implementer within src/charter/compiler.py's existing output shape)	list[str]	Charter compiler	The resolved, canonical set of governed languages, computed once at charter generate/charter sync time from the interview answers available at that moment, and persisted alongside/within the compiled charter output.

State transition:

[no charter] --(interview)--> [interview answers only]
                                   |
                                   | charter generate / charter sync
                                   v
[compiled charter WITHOUT languages field]  (pre-existing projects, until first recompile under this change)
                                   |
                                   | charter generate / charter sync (post-change)
                                   v
[compiled charter WITH languages field]  <-- canonical runtime source from here on

Runtime resolution invariant (infer_repo_languages / its replacement):

1. If the compiled charter has a structured languages field → return it. This is authoritative; the interview transcript is never consulted once this exists, even if it disagrees. 2. Else (no structured field yet — pre-recompile projects) → fall back to today's extraction logic (interview transcript, then charter.md free-text as a secondary fallback), preserving current behavior for projects that have not yet recompiled under this change.

Consumers (read-path only, no logic change expected):

• src/charter/context.py:1320,1326 — active_languages population, feeding _diagnose_catalog_miss/classify_scope_filtered_miss (context.py:2188-2207).
• src/charter/compact.py:195 — display-only footnote, wrapped in a defensive exception handler.

Test contract change: tests/charter/test_language_scope.py::test_infer_repo_languages_prefers_interview_answers — inverted to assert charter-authoritative resolution when interview and compiled charter disagree, plus a new case exercising the structured-field path directly.