v0.9.1

fix(npm): let an unproven package name fail without failing the release

v0.9.0 died on `403 — Package name too similar to existing package cp-cli`.
npm applies a typosquatting similarity check that runs only on a real publish:
`npm view scc-cli` returned 404 and `npm publish --dry-run` passed, and neither
says anything about it. Because the rejected name published first, `set -e`
took `@protonspy/scc` down with it — six platform packages reached the registry
at 0.9.0 with no launcher that resolves them, and no tag was cut.

LAUNCHERS entries now carry `required`, and the tiers are directories so both
publish order and failure policy are visible in the layout: dist/scc-*/, then
dist/launchers/, then dist/launchers-optional/. A required name is already ours
and a failure there is real; an unproven one is attempted last and warns.

The corollary is the load-bearing half: only a required name may appear in
documentation, the embedded entry.md included. Pointing an install line at a
package that might be refused is the same bug somewhere more expensive, so the
docs go back to @protonspy/scc and `spec-claude-code-cli` ships untested and
undocumented. Promote it in the release after the one that proves it publishes.

Template version stays 9 rather than bumping: no v0.9.0 binary is reachable —
the tag and GitHub Release steps were skipped, and no launcher on the registry
resolves the orphaned platform packages — so the v9 that named scc-cli never
shipped to anyone and is corrected in place.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J54qbk8RpC2tZH8LBz6T2b