Topdata Migration (#2)

Native topdata migration summary

- Replaced the legacy 2dabuilder runtime path with the native topdata builder.
- Native build, validate, compare, and convert flows now cover the canonical topdata pipeline.
- compare-topdata is now a native self-check; legacy reference-builder runtime usage was removed.
- Parts generation follows the native asset-scan contract and uses sow-assets via project asset resolution.
- Generated feat families, class-feat injects, masterfeat/successor expansion, and dataset-derived feat generation were brought to parity and regression-covered.
- Remaining mirrored datasets were migrated into native-owned canonical data while preserving lock IDs.
- normalize-topdata bridge behavior and migration-era ownership markers were removed.
- Documentation was rewritten around the native workflow and active contracts were cleaned up.
- Final hardening pass removed stale validator assumptions and cleaned ignored/generated artifacts for PR readiness.

Reviewed-on: https://gitea.westgate.pw/ShadowsOverWestgate/sow-tools/pulls/2
Co-authored-by: vickydotbat <vickydotbat@tutamail.com>
Co-committed-by: vickydotbat <vickydotbat@tutamail.com>

internal/topdata/MASTERFEATS_CONTRACT.md

@@ -0,0 +1,70 @@
+# `masterfeats` Canonical Contract
+
+`masterfeats` is a stable native canonical family consumed directly by `feat`
+generation, class-feat expansion, and inheritance/ref resolution.
+
+Current canonical scope:
+
+- dataset root: `topdata/data/masterfeats/`
+- required files:
+  - `base.json`
+  - `lock.json`
+- generated output:
+  - `masterfeats.2da`
+
+## `base.json`
+
+Canonical shape:
+
+```json
+{
+  "output": "masterfeats.2da",
+  "columns": ["LABEL", "STRREF", "DESCRIPTION", "..."],
+  "rows": [
+    {
+      "id": 0,
+      "key": "masterfeats:weaponfocus",
+      "LABEL": "WeaponFocus",
+      "STRREF": "6490",
+      "DESCRIPTION": "436"
+    }
+  ]
+}
+```
+
+Rules:
+
+- `output` must be exactly `masterfeats.2da`
+- `columns` must include `LABEL`, `STRREF`, and `DESCRIPTION`
+- every canonical row must have a non-empty `key`
+- row keys must start with `masterfeats:`
+- inline TLK payloads are allowed in `STRREF` and `DESCRIPTION`
+- numeric/text references are both allowed where the native TLK compiler already supports them
+
+## `lock.json`
+
+Canonical shape:
+
+```json
+{
+  "masterfeats:weaponfocus": 0
+}
+```
+
+Rules:
+
+- every key must start with `masterfeats:`
+- every value must be numeric
+- the lockfile remains the canonical stable id source for authored keys
+
+## Module contributions
+
+This family continues to support the shared canonical module shapes already used by native
+datasets:
+
+- `entries`
+- `overrides`
+- `rows`
+
+Those shapes are validated generically in `topdata.go`; this contract only adds the
+family-specific guarantees for `masterfeats`.