okf v0.5.0 — OKF v0.2, --migrate, --max-warnings

Changed

• The toolkit now targets OKF v0.2. skills/okf/reference/SPEC.md is
  re-vendored verbatim from upstream 3fcbb9f, and the okf, validate, and
  visualize skills apply its rules. Conformance is unchanged in substance
  (parseable frontmatter with a non-empty type) but has moved from §9 to §11;
  validator messages cite v0.2 section numbers throughout.
• okf_init.py scaffolds v0.2 frontmatter — okf_version: "0.2" in the root
  index, status and generated: {by, at} (actor process:okf_init) on the
  starter concept.
• examples/sample-bundle and this repo's own .okf bundle are migrated to
  v0.2; the two GitHub Pages demos are regenerated from them. The sample bundle's
  checkout conversion metric now records the orders database in sources, so the
  live demo shows a derivation edge.

Added

• validate: checks for the new families, all soft — generated.by present,
  every verified entry has an actor (a bare mapping counts as a one-element
  list, §5.2), status is one of draft/stable/deprecated, stale_after and
  sources[].last_modified are absolute YYYY-MM-DD dates, every sources
  entry has a resource, every [^label] footnote names a sources[].id, and
  an Attested Computation declares a runtime.
• visualize: the detail panel renders status, generated, verified,
  stale_after, and a Sources list with each source's credibility signals; a
  sources entry pointing at another concept in the bundle also becomes a graph
  edge.
• validate --migrate: rewrites a v0.1 bundle to v0.2 in place — timestamp to
  generated: { by: process:okf-migrate, at }, a # Citations list up into
  sources, okf_version to 0.2. Textual, so comments, key order and quoting
  survive a migration; idempotent, so a half-migrated bundle converges. It does
  not invent generated.by for pre-v0.2 content (the process: actor leaves the
  concept correctly unverified under §5.3) and cannot recover per-claim
  [^id] attribution, which v0.1 never encoded — the command says so.
• validate --max-warnings N: the gate between a default that fails on nothing
  and a --strict that demands zero, so a bundle with known warnings can still
  be gated in CI. --strict is the N=0 case.
• make docs pins the exact invocation behind the two GitHub Pages demos, and CI
  fails on a stale docs/. They had silently drifted: both live pages were
  serving a build from before the DOMPurify sanitize fix.

Compatibility

• v0.1 bundles still validate and render. The two superseded constructs are
  read, not rejected: a legacy timestamp is used as generated.at, and a body
  # Citations list is recognized. Both are reported as warnings naming their
  v0.2 replacement (§13.1).
• --strict fails an unmigrated v0.1 bundle. That is the migration nudge and
  it is deliberate — templates/CLAUDE-okf.md tells every user to run --strict
  before committing, so --migrate ships in the same release to make it a door
  rather than a wall. Note that §11 conformance itself never mentioned
  timestamp or # Citations: a v0.1 bundle is conformant under v0.2 either way.