v0.11.1 — dynamic tool guide and memory store caps

[lavindeep]

Summary

• Dynamic tool guide (PROMPT_VERSION 6): a compact, registry-derived Tool guide block in the system prompt. Rendered from the same profile-filtered definitions offered to the model, so it cannot drift from the actual toolset; optional tools (memory_*, web_*, skill_read) appear only when registered, and update_plan appears only while a plan is active or blocked, preserving the proposal-vs-execution split. ~82 tokens for the default toolset.
• Memory store file cap: memory.json (global and project separately) is capped at 1800 serialized characters. Writes that would exceed the cap are rejected with a clear instruction to forget or compact first. The cap ratchets against the normalized current payload size, so legacy over-cap stores can always shrink (forget keeps working) while growth stays rejected until the store complies.
• Atomic /memory compact: replacements are preflighted for every store before any file is written — a rejected optimization can no longer partially mutate global memory while leaving project memory untouched.
• Scoped memory rendering + guidance: the injected memory block now groups global vs project preferences into distinct sections, and memory_propose_update documents the global-vs-project scope policy in its tool description.
• Friendly cap-rejection messages on /memory add, /memory forget, and /memory compact.

Testing

• Full gate green at HEAD: ruff check, ruff format --check, mypy --strict, 1625 tests (up from 1610).
• New coverage: cap rejection on fresh stores, legacy over-cap stores shrinking via forget (including minified legacy files), growth rejection while over cap, atomic multi-store compact rejection, grouped memory rendering, tool-guide presence/absence per registered toolset.
• Live acceptance: validated in a live session on a real terminal.

Docs

DESIGN.md updated in the same commit: ContextAssembler block order (tool guide), §16 memory cap + ratchet + atomic compact, §19 prompt rationale (PROMPT_VERSION 6).