v0.7.4 — OpenCode v1.15.x compatibility + JS plugins

Breaking (config schema)

• Removed \plugins\ (old object format) and \hooks\ keys from opencode.json — OpenCode v1.15.x rejects them
• Changed \skills.directories\ → \skills.paths\ for schema compliance
• Added \\ reference

New: Native JS plugins for OpenCode

• \gstack-security.js\ — Security guardrails via \ ool.execute.before\ (blocks dangerous commands, auto-approves safe ones) + error review via \ ool.execute.after\
• \gstack-session.js\ — Update check on \session.created\ + chronicle save on \session.deleted\
• \gstack-prompt.js\ — Skill suggestions via \ ui.prompt.append\ based on prompt keywords

Fix

• Root cause: \mergeJson\ in \merge.js\ used Set-based dedup which failed for arrays of objects, causing duplicate plugins on every reinstall