The real moat of metadata-driven development is not 'low-code UI', it
is that the entire business system is small enough to fit in an AI
agent's context window. Make this an explicit, top-level value across
README and the concept docs.

- README.md
  - Add a 'Key Features' bullet on ~100x less code -> AI maintainability
  - Add 'Code footprint' and 'AI maintainability' rows to the
    Retool/Appsmith comparison table
  - Rewrite the 'Why AI-native?' intro to anchor the value on
    'fit in an agent's context window'

- content/docs/index.mdx
  - Add a second callout under the 'not a low-code UI builder' line
    explaining the ~100x code reduction and AI-co-maintenance angle
  - Fix stale 'npx @objectstack/cli init' -> 'npx create-objectstack'
    quick-start command (matches updated README)

- content/docs/concepts/metadata-driven.mdx
  - Rename benefit #4 'Reduced Boilerplate' -> '~100x Less Code -
    Sized for AI Agents' and reframe around context-window fit
  - Clarify that what gets generated is full CRUD + REST + typed SDK
    + MCP tools + validation + permission scaffolding, not just CRUD

- content/docs/concepts/north-star.mdx
  - Add a sixth non-negotiable tenet: 'Compact by Construction'
    -> a typical enterprise app fits in ~1% of a hand-written
    equivalent, small enough for an AI agent to load and refactor
    end-to-end. Explicitly call this out as the real moat.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Introduces an opt-in path in ObjectStackProtocolImplementation.saveMetaItem
that writes overlay metadata through SysMetadataRepository.put instead of
the raw engine, so writes append to the change-log and emit HMR seq events.

Behavioural changes (all behind options.useRepositoryWritePath /
OBJECTSTACK_USE_REPOSITORY_WRITE_PATH=1):
- saveMetaItem request gained optional parentVersion (If-Match) and
  actor fields. ConflictError -> 409 metadata_conflict.
- Plural type aliases (views, dashboards, ...) normalized to singular
  before the repo's overlay-allowlist gate (rubber-duck #5).
- Object-registry mutation moved AFTER successful put() so a conflict
  does not leave the in-memory registry stale (rubber-duck #3 invariant
  test added).

Repo/test-fake fixes uncovered by rubber-duck review:
- SysMetadataRepository.put/delete now update/delete by row id because
  the engine's strict .update requires id or multi:true (rubber-duck #1).
- sys_metadata.checksum column widened from 64 -> 71 chars to hold the
  sha256: prefix produced by hashSpec() (rubber-duck #2).
- Three test fake engines extended to support both overlay-tuple and
  id-based where lookups.

333/333 objectql tests pass.

Deferred to PR-10d.4: REST plumbing for parentVersion/actor
(rubber-duck #6), race-window retry for omitted parentVersion
(rubber-duck #4), default flag flip + legacy path removal.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Proposes that every Action opts in to AI exposure via a single `ai:` block
on ActionSchema, and the runtime auto-derives AIToolDefinitions from the
existing ActionRegistry. Eliminates the need to maintain parallel skill /
tool code for every business operation an admin can already perform.

- Adds opt-in `ai: { exposed, description, paramHints, outputSchema, ... }`
  block to @objectstack/spec ui/action.zod.ts
- Adds ActionRegistry.toolsForAi(opts) in @objectstack/runtime
- Wires service-ai/agent-runtime to merge action-tools into availableTools
- Routes LLM tool_calls with meta.kind='action' through ActionRegistry so
  permissions, validation, hooks, audit, and transactions all apply uniformly
- Confirmation defaults derived from existing confirmText / type='delete'

Authored from HotCRM v1.1 planning. HotCRM will be the first consumer:
delete src/skills/, convert each business skill to defineAction with ai
exposed, ship the 'Operational Parity' story as Wow #4.

Refs ADR-0003, ADR-0008, ADR-0009, ADR-0010.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>