v0.6.0 — human-readable Issue titles

[0.6.0] — 2026-06-17 — Human-readable Issue titles

Spec Issues now read like features, not filenames. Additive and default-on;
extension.id stays linear; the command surface is unchanged; existing
installs re-title once on the next reconcile, then stay zero-churn. All safety
guarantees (idempotency, drift-awareness, fail-closed writes) hold.

Human-readable Issue titles — spec 012

• The board reads like features, not filenames. Spec Issues are now titled
  <NNN> — <name> (e.g. 006 — Faithful projection) instead of the directory
  slug 006-faithful-projection. The name comes from the spec's
  # Feature Specification: H1; when that's the unfilled [FEATURE NAME]
  placeholder it falls back to the first sentence of the **Input**: lede
  (length-capped to one line), then to the slug as a last resort.
• Deterministic + default-on. The title is derived purely from the spec on
  disk — no summarization model — so it is identical across hook, manual, and
  headless-CI reconciles and is zero-churn on re-run. No config, no opt-out: on
  the first reconcile after upgrade each existing Issue re-titles once
  (slug → readable), then stays stable. Sub-issue titles, the description, and the
  speckit-spec:NNN identity label are unchanged. Parity-locked with the
  spec-kit-jira sibling; extension.id stays linear.