v2.9.0 — Supersede at the source: the retire reminder

Supersede at the source

Anchoring stops features from vanishing; superseding stops stale directives from causing reverts. A retired requirement gets struck out by update retire, but the prose that described its old behavior — the originating spec sentence, the CRC bullet, the sequence step — has no forcing function. It rots in place until a future agent reads it as current intent and "fixes" the code back to match, undoing the very change that obsoleted it. This release closes that gap on two layers.

Skill

• New Core Principle "Supersede at the source" — the mirror of "No unanchored design" — plus a "Why superseding matters" section.
• Migration retirement steps generalized beyond migrations: step 5 points at the reminder; step 6 now reconciles the originating spec prose (via **Source:**) as well as design prose and applies to every retirement; step 7 gains a prose-grep precondition and a completion test.

Tool

• minispec update retire now prints a supersede-at-source reminder to stderr (suppressed by --quiet) naming the retired requirement's **Source:** spec, prompting the design-prose grep, and stating the completion test. stdout stays just the Tn, so callers that capture the retirement ID are unaffected.

Install

• Skill: download mini-spec-v2.9.0.zip and unzip into your project root (or ~/.claude).
• Tool: download the minispec-* binary for your platform, mark it executable, and put it on your PATH as minispec (e.g. ~/.claude/bin/minispec).
• Companion: claude plugin install code-simplifier