#47 release create: enforce v-prefix + record sha (self-sufficient releases)

SOURCE: wr1te round 3 + orchestrator probe (verified): f0rge release create 0.2.0 writes .forge/releases/0.2.0.md while the convention (all records + install tags) is v-prefixed; nothing validates. FIX: release create ENFORCES the v prefix — create 0.2.0 -> one-line usage error "versions use the v prefix: v0.2.0", exit 2, try-path hint. Loud over silent (same philosophy as create --state). ALSO: records gain sha (HEAD at create time) so releases are self-sufficient — install resolution stops depending on git tags (nothing ever created them; they were orchestrator habit). Spec [release]: Required version, created; Optional title, sha. Golden fixture updated (sha optional; old records parse fine). DONE: create 0.2.0 fails loudly; create v0.2.0 writes v0.2.0.md with sha; no tags needed for resolution.