fix(3.3): reconcile spec/schema/core handler-type drift + userConfig/settings dupe + stale dep pins

[espetro]

Problems

Three distinct schema/code sync issues:

1. Handler-type drift

• Spec $defs/hookHandler lists command | http | reference
• Core (packages/core/src/types.ts:211-238,309) implements command | http | inline + dangling file literal; no reference
• Reconcile across: spec/v1/manifest.schema.json, packages/schema/schemas/manifest.schema.json, core types

2. userConfig vs settings duplication

• packages/core/src/types.ts:34 has userConfig
• packages/core/src/types.ts:37 has settings
• Resolve: pick one canonical name, remove the other, update all references

3. Stale ^0.1.0 dep pins

• packages/cli/src/commands/init.ts pins @agentplugins/* at ^0.1.0 for scaffolded plugins
• Update to current semver

Acceptance criteria

• spec/v1/manifest.schema.json and packages/schema/schemas/manifest.schema.json agree on handler types
• Core types match the spec; no dangling file literal; reference type added if spec-mandated or removed if not
• userConfig/settings resolved to one canonical name with no duplication
• init.ts dep pins updated to current semver
• Coordinate with Epic [Epic] Plugin Portability & Compat Layer — v0.3.0 P0 #24 Lane A so schema is touched only once
• pnpm build && pnpm -r test && pnpm -r typecheck green

Classification

• Type: bug
• Effort: M
• Branch: feat/v0.3.0-authoring-wins
• Milestone: v0.3.0 (Stage 1 — item 3.3)