v1.1.0 — skills, deferred tools, search_tools

Contract changes are additive: a request that does not use the new fields behaves exactly as
before.

Added

• Skills (RFC 0001, SPEC §6.8). skills[] in
  the request, in the SKILL.md shape: { name, description, body, tools }. The engine appends
  an index (name and description, sorted by name) to system and offers a built-in tool
  load_skill. It returns the skill's instructions and makes the skill's tools available from
  the next step.
• Deferred tools. tools[].defer_loading: true keeps a tool out of the model's context
  until a skill or a search activates it. A call to a tool that is not loaded yet gets
  tool_not_loaded: it is not executed, does not count toward max_tool_calls and is not
  treated as a repeat.
• search_tools. A built-in tool offered when a deferred tool belongs to no skill. It runs
  BM25 over tool names, descriptions and argument names, works the same on every provider and
  is reproducible from the request. Matches activate from the next step; matches that belong to
  a skill point the model to load_skill.
• The prompt cache survives activation. On Anthropic models with tool search, activated
  tools arrive as tool_reference blocks inside the conversation, so the cached prefix never
  changes. On other providers the next step's tools array grows: one prefix cache miss per
  activation.
• Still stateless. What is loaded is derived from the history on every run, from tool
  messages the engine marks builtin: true (harness obligation H20). Trimming never drops a
  turn that carries an activation in effect.
• Built-in calls appear in tool_calls[] with builtin: true. New journal events:
  skill_loaded, skill_unknown, skills_restored, tool_search,
  builtin_history_invalid.
• examples/sqlite-harness: a complete harness on SQLite with no
  dependencies, end to end, with a chat in the terminal (npm run example:sqlite).

Changed

• Vercel AI SDK 6 (ai 6.0, @ai-sdk/anthropic 3.0, @ai-sdk/openai-compatible 2.0).
  Usage is read from the SDK's unified split of uncached, cache read and cache write tokens;
  billing still records the uncached input (SPEC §8.1). On tool_choice: none steps Anthropic
  now keeps the tools array and receives tool_choice: { type: "none" }.
• README: a banner, badges, a comparison with neighbouring tools, and a quickstart with the
  published image.

Docker: ghcr.io/paveler/theloop:1.1.0 (also 1.1, 1, latest).