Build registry-driven wrangle documentation

[ebhills]

Summary

• Establish the Registry as the source for generated wrangle documentation and machine-readable contracts.
• Organize 98 runtime wrangles into 17 namespace pages while retaining direct entry pages and raw public artifacts.
• Add explicit parameter groups, lifecycle replacements, integrated input/output examples, playground actions, and shared Registry page styling.
• Mark maths as replaced by math and standalone standardize as replaced by standardize.custom.
• Define separate migration plans for retiring the previous _sources documentation workflow and moving schema authority from hand-maintained WranglesPY _schema content to the Docs Registry.
• Replace the transient Registry Pilot framing with an explicit pre-production contract and measurable production-readiness criteria.

Behavior and compatibility

• Existing /wrangle documentation pages and routes remain available; this PR does not deploy the site or perform the final route cutover.
• The /wrangles navigation is labeled Registry and favors namespace-grouped pages with stable wrangle anchors.
• Parameters appear immediately after each wrangle definition, followed by examples and supporting details.
• All 98 Registry entries are treated consistently. bootstrap:registry creates missing records only and never overwrites existing authoritative records.
• The generated pre-production recipe schema moves from /schemas/recipes/pilot/schema.json to /schemas/recipes/registry/schema.json.
• WranglesPY remains authoritative for callable signatures and runtime behavior while the Registry becomes the editorial authority for guidance, constraints, examples, access, lifecycle, and provenance.

Validation

• npm run bootstrap:registry — created 0 records and preserved all 98 existing entries.
• npm run check:registry — passed; all 327 generated artifacts are current.
• npm run typecheck — passed.
• npm run build — passed and produced the Registry index plus namespace and direct-entry routes.
• git diff --cached --check — clean before commit.
• Branch was verified 0 commits behind origin/main before push.

Known warnings

The production build succeeds with pre-existing Docusaurus configuration, Browserslist, and old Excel/Python documentation link warnings. No new Registry broken-link warning was introduced.

Remaining work

The Registry remains pre-production. Issue #27 tracks the _sources retirement, schema-consumer cutover, UUID completion, example execution verification, immutable public artifacts, and the first production Registry release.

Wrangle descriptions and examples also remain subject to later editorial curation. This PR completes the roughly 80 percent Registry and presentation foundation intended for that follow-on work.

Closes no issue; tracks remaining cutover work in #27.

Rollback

Revert this PR to restore the previous Registry generation, presentation, and pilot-path behavior. Existing /wrangle documentation is not removed by this change.