refactor: extract all generators into independent TOOLS/ modules

Each generator is now a standalone Go module with its own go.mod:

TOOLS/
├── yaml-generator/       ← service_spec_gen (API → YAML)
├── resource-generator/   ← gen_v2 (YAML → Go resources)
├── docs-generator/       ← docs_template_gen_v2 (YAML → Markdown)
├── ops-generator/        ← ops_docs_gen (ops documentation)
└── bin/                  ← pre-built binaries

All scripts updated to use TOOLS/bin/* binaries.
Removed old universal_rebuild/tools/ and universal_rebuild/bin/.

.gitignore

@@ -88,3 +88,4 @@ universal_rebuild/service_params_gen
 # ── Build artifacts ──
 terraform-provider-mycloud
 artifacts/api-meta/*/errors.log
+TOOLS/bin/