docs(spec): bring MASTER_SPEC up to date through V2, and version it (#153)

MASTER_SPEC.md lived outside version control (in the parent directory), so it had
no history and the README's ../MASTER_SPEC.md link was broken on GitHub. It is now
tracked at the repository root and the links are fixed.

Content updated from 'Version 1 / Draft' to 'Version 2 / Maintained'. Chapter and
section numbers are deliberately unchanged so the wiki's existing § references stay
valid; superseded chapters are marked in place rather than deleted:

- New 'Document Status & Version History' section with a per-release change table.
- §3: three new design principles capturing the V2 shift — 3.13 Fidelity,
  3.14 Automation Without Gates, 3.15 Ask Only What Matters.
- §8: pipeline reduced to three stages; stages 4-5 retained as historical.
- §17 Resolver: now the final stage. Adds modifier preservation, the config-gated
  deduplication, the opt-in semantic fallback with its four normative guarantees,
  prompt translation, and the output-preserving performance rules.
- §18/§19: Category Splitter and Prompt Builder marked superseded; the category
  list stays normative as traceability metadata; new §19.7 specifies the flat prompt.
- §20: eight nodes -> five, with real inputs/outputs and the KB Editor constraints.
- §23: current config document, plus a new §23.4 recording which fields are
  deliberately not exposed and why.
- §15: new §15.13 specifying automatic KB construction with no approval gate.
- §13: new §13.13 fidelity rules (lists, relations, conjunctions, explicit content).
- §9/§11: Category Map and Prompt Output data model + schemas marked removed;
  Knowledge Base Manifest schema added.
- Appendix B: documents SC0015-SC0022.
- §30: V1 and V2 marked delivered; records that the automatic KB builder shipped
  deliberately without the originally specified manual-validation gate, that
  localization was dropped, and that the Entity Graph was not pursued.

Co-authored-by: kunail0804 <kunail0804@gmail.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -225,9 +225,9 @@ In-repo notes live in [`docs/`](docs/) — see [`docs/nodes.md`](docs/nodes.md)
 node reference and [`docs/knowledge_base_build.md`](docs/knowledge_base_build.md) for
 how the Knowledge Base is regenerated.
 
-[`MASTER_SPEC.md`](../MASTER_SPEC.md) is the original design specification. It records
-the V1 design intent; where it and the shipped code disagree, the code and this
-documentation win.
+[`MASTER_SPEC.md`](MASTER_SPEC.md) is the full normative specification, maintained
+through Version 2. Chapters superseded by later versions are marked in place rather
+than deleted, so the original design intent stays readable.
 
 ---
 

docs/README.md

@@ -3,10 +3,11 @@
 Project documentation is maintained primarily in the
 [GitHub Wiki](https://github.com/kunail0804/ComfyUI-Scene-Compiler/wiki).
 
-[`MASTER_SPEC.md`](../MASTER_SPEC.md) at the repository root is the original design
-specification: it records the Version 1 design intent and is kept for reference.
-Where it and the shipped code disagree, **the code and this documentation win** —
-V1.1 and V2 changed parts of the pipeline (see the [Roadmap](https://github.com/kunail0804/ComfyUI-Scene-Compiler/wiki/Roadmap)).
+[`MASTER_SPEC.md`](../MASTER_SPEC.md) at the repository root is the full normative
+specification, maintained through Version 2. Chapters that later versions superseded
+(the Category Splitter and Prompt Builder stages, the Knowledge Base Loader node) are
+marked in place rather than deleted, so the original design intent stays readable
+alongside what ships today.
 
 This `docs/` directory holds documentation that is **not** part of the wiki —
 developer guides and generated references.