Remove an internal reference doc + scrub working-coordination / internal-spec leaks from the public tree

[styk-tv]

The public tree carried an internal reference doc not intended for publication, plus scattered references to internal working-coordination notes and unreleased internal specs across tracked docs and tests.

• Remove the internal reference doc from tracking (content kept locally).
• Scrub working-coordination / internal-spec / cross-repo internal references from tracked docs, test fixtures, and example URNs (use generic demo identifiers).
• Verify zero internal references remain in the tracked tree.

State: implemented, staged for the v1.5.3 commit.

[styk-tv]

Active public surface is clean as of fccb268: internal reference doc removed, FUTURE/roadmap planning specs un-tracked, and shipped specs + client code + tests + dev docs scrubbed of internal references. Verified: a leak scan of the tracked tree (excl. vendor + CHANGELOG) returns only the .gitignore _WIP/ ignore-rule.

Remaining: CHANGELOG.md historical entries still reference internal working-coordination filenames (12 occurrences). Because CHANGELOG ships in the npm tarball (package.json files), this is folded into the npm go-live (#4): decide there whether to (a) scrub the historical references, or (b) drop CHANGELOG from the published files set. Keeping this issue open until then.

[styk-tv]

Closing statement. Completed across three increments on main — 296296b (remove non-public material + scrub the active surface, incl. the shipped ck.js header), fccb268 (un-track planning specs), c938300 (scrub CHANGELOG history entries). The entire tracked tree now scans clean; the only remaining pattern hit is the .gitignore rule itself (the exclusion mechanism, not content). Shipped in v1.5.3 (attested, byte-verified: image layer = ck.js + ck-client.js + ck-store.js + vendor/* + README/LICENSE only).

Boundaries going forward. The disclosure policy this work enforced is now codified in PROVENANCE.md — public references are made by public surface only (verb / version / OCI digest / repo: pgCK, pgRDF, oci-germination, sporaxis). Git history prior to these commits is immutable and was not rewritten; the guarantee applies to the active tracked surface and everything shipped from v1.5.3 onward.