v2.0.0

Breaking changes:

• Rename the plugin from skills to causa, so its skills are namespaced as causa:<skill>.
• Restructure delivery into two stages, each ending in a single human gate on complete, already-reviewed work: design (clarify, design every contract, review, fix), then implementation (plan, code, document, review, fix). build-feature now orchestrates both and writes the contracts itself, rather than invoking a gated design skill per artifact.
• Turn the design skills into pure knowledge references: design-model, design-api-http, design-api-firestore, design-state, design-scenario, and design-timeline lose their personas, <objective> blocks, questioning steps, and confirmation gates, and their <output> sections now describe the artifacts on disk rather than a work-directory document. Gates belong to whoever is talking to the human.
• Replace the per-skill design documents with a single design.md, written by build-feature.
• Move access patterns, indexes, triggers, and the whole of causa.yaml into the design stage. plan-implementation no longer writes causa.yaml and is limited to code architecture.
• Replace plan-tests' test skeletons with a list of the behaviors to cover, derived from the contracts and written during design. How a behavior is tested is now decided while writing the code.

Features:

• Define the review-design and review-implementation skills: adversarial reviewers that always run in a context holding none of the author's rationale, ground every finding in cited evidence and a concrete failure scenario, and must attempt to refute each finding before reporting it.
• Define the improve-skills skill, which turns the review findings, deviations, and human feedback that were kept into minimal skill deltas, and routes repository-specific lessons to the repository's own memory instead of discarding them. It stops at a self-contained skill-feedback.md, leaving the edits to an agent working in the plugin's own repository.
• Define the design-triggers skill, covering the events a service consumes, the tasks it enqueues, and the crons it runs. It is independent of design-model: a new topic needs no consumer, and a trigger on another domain's topic needs no contract.
• Add access patterns to design-state, listing every way the feature reads data — including the lookups from event handlers, crons, and internal logic that are invisible from the API contracts — so that indexes are justified by a query rather than guessed.
• Add a bundled question inventory to build-feature, asked in two waves — scope first, then only the surfaces in scope — with an assumption ledger in requirements.md for everything not asked.
• Record deviations from the implementation plan in implement, each with whether the plan could have anticipated it. The plan is a briefing, not a specification.
• Add a feedback.md journal, appended to by build-feature and implement as corrections happen, so improve-skills reads a log instead of reconstructing one.
• Add validation checklists to the bump-version and document skills.
• Add a Spanner DDL example to the design-state skill, and document the table name override, row deletion policies, and interleaved tables.
• Make the skills portable across harnesses, by conforming to the Agent Skills open standard rather than to Claude Code's extensions.

Fixes:

• Correct the errorCode property description in the design-api-http skill, which duplicated the statusCode one.
• Pass --no-git-tag-version to npm version in the bump-version skill, so it no longer creates a commit and tag that conflict with the following step.
• Declare the JSONSchema examples as draft 2020-12, the first draft to define the $defs keyword they use.
• Add the missing usage triggers to the implement and plan-tests descriptions.
• Fix a typo in the design-scenario skill.
• Fix the step numbering in the design skills, where a nested list restarted the outer sequence.
• Reference the timeline JSONSchema from the design-timeline skill and its example, matching the design-scenario skill.
• Replace the skill reference appendix in the build-feature skill with a table of skill outputs, dropping guidance already carried by each skill's description.

Chores:

• Complete the plugin and marketplace manifests and add a license.