ADR-306: Extract component-taxonomy skill; retire test-driven-development

[jodavis-claude]

Work item

ADR-306: Extract the Wrapper/Testable/Orchestrator tier definitions out of
_spec_TddForImplementation.md into a new, standalone component-taxonomy skill, and retire
test-driven-development entirely by splitting it into behavior-driven-development (the
E2E-first / E2E-confirm wrapper) and tdd-practices (the AAA / red-for-the-right-reason /
frozen-Arrange-Act / naming rules) — then sweep every already-merged reference site to point at
the correct successor.

Changes

• plugins/dev-team/skills/component-taxonomy/SKILL.md (new) — Wrapper/Testable/Orchestrator
  tier definitions, the property-level Wrapper carve-out, and the "classifies production
  components only" paragraph, moved verbatim from the spec's "Component taxonomy" decision.
  user-invocable: false, no argument-hint.
• plugins/dev-team/skills/behavior-driven-development/SKILL.md (new) — former step 1 (write
  E2E/API tests first) and step 3 (confirm E2E tests pass) of the retired
  test-driven-development skill, renumbered 1–2. Kept argument-hint: <task context or exit criteria> from the retired skill.
• plugins/dev-team/skills/tdd-practices/SKILL.md (new) — former "Practice rules" section (AAA
  structure, red-must-fail-for-the-right-reason, frozen-Arrange/Act, naming convention),
  byte-identical to the retired skill's four rule bodies.
• plugins/dev-team/skills/test-driven-development/SKILL.md — deleted.
• plugins/dev-team/skills/spec-first-draft/SKILL.md — replaced the inline
  Wrapper/Testable/Orchestrator bullet list with a one-sentence invocation of
  component-taxonomy. Component Breakdown table template and isolation-pattern authoring
  guidance left unchanged (ADR-297's scope).
• plugins/dev-team/agents/tdd-tester.md, agents/tdd-implementer.md, agents/tdd-refactorer.md
  — test-driven-development citations renamed to tdd-practices.
• plugins/dev-team/skills/tdd-red-turn/SKILL.md, skills/tdd-refactor-turn/SKILL.md — build/
  test-command sentence drops the test-driven-development half (now cites
  code-change-expectations alone); Skills-list citation renamed to tdd-practices.
• plugins/dev-team/skills/tdd-green-turn/SKILL.md — three citations: inline "Practice rules"
  reference and Skills-list entry renamed to tdd-practices; build/test-command sentence drops
  the test-driven-development half.
• plugins/dev-team/skills/implement-tdd/SKILL.md — stale no-Components-in-scope fallback bullet
  removed outright; build/test-command sentence drops the test-driven-development half;
  "E2E re-run" reference renamed to behavior-driven-development; bundled Skills-list bullet
  split into two, citing tdd-practices and behavior-driven-development separately.
• plugins/dev-team/skills/code-change-expectations/SKILL.md — TDD pointer now points at
  implement-task's dispatcher instead of the retired skill (the instruction described the
  retired step-2 procedure, not a straight rename).

Design decisions

• Kept tdd-practices's Practice rules section literally unchanged (4 bullets) rather than
  adding a new "logging" bullet — the exit criterion's parenthetical restates epic-level context;
  logging already lives solely in code-change-expectations's coverage checklist.
• spec-first-draft's replacement text is a short pointer sentence to component-taxonomy;
  isolation-pattern authoring guidance stays inline (ADR-297's scope).
• behavior-driven-development's step 2 wording is a deliberate reword ("Once implementation is
  complete" instead of "Once all components are implemented") to avoid a dangling reference to
  the dropped per-component step.
• component-taxonomy and tdd-practices follow the code-change-expectations/
  missing-test-harness reference-skill convention (user-invocable: false, no
  argument-hint); behavior-driven-development keeps the retired skill's argument-hint.
• Scope discipline verified: grep -rl test-driven-development plugins/ after all edits returns
  only plugins/dev-team/skills/implement-task/SKILL.md, which is explicitly out of scope
  (belongs to ADR-303's still-open PR ADR-303: Rewrite implement-task as a per-component dispatcher, add implement-direct #54). plugin.json version bump is out of scope (ADR-304).
• No unit tests or E2E scenarios: this is repo-internal agent-skill/prose reorganization with no
  runtime code and no existing test harness for skill prose; verified instead via dry runs
  (verbatim-move diff checks, reference-sweep grep check, and a synthetic
  spec-first-draft Component Breakdown dry run), documented in the task's work summary.

[github-actions]

build-and-test: Python test results

Status: ✅ Passed

Test log

[jodavis-claude]

Reviewed ADR-306 against its exit criteria (task brief in the workflow context file) and CONTRIBUTING.md. All 10 exit criteria are met:

• component-taxonomy/SKILL.md — Wrapper/Testable/Orchestrator tiers + property-level Wrapper carve-out, verbatim from the spec (diffed byte-for-byte).
• behavior-driven-development/SKILL.md — former steps 1/3 of test-driven-development, renumbered 1-2; step 1 verbatim, step 2 deliberately reworded to drop a dangling reference to the removed per-component step (documented).
• tdd-practices/SKILL.md — four rule bodies (AAA, red-for-the-right-reason, frozen-Arrange/Act, naming) byte-identical to the retired skill.
• test-driven-development/SKILL.md deleted; grep -rl test-driven-development plugins/ on the branch returns exactly implement-task/SKILL.md, matching the expected post-task state.
• spec-first-draft/SKILL.md now invokes component-taxonomy instead of restating tiers inline.
• tdd-tester.md/tdd-implementer.md/tdd-refactorer.md, tdd-red-turn/tdd-green-turn/tdd-refactor-turn, implement-tdd/SKILL.md, and code-change-expectations/SKILL.md all carry exactly the citation treatment the brief specifies (verified line-by-line).
• Dry runs for the verbatim moves, the reference sweep, and the synthetic spec-first-draft Component Breakdown scenario are all documented in the work summary.

Two non-blocking notes below (one process/sequencing risk worth eyes-on, one minor self-review accuracy nit) — inline comments follow. Approving; neither blocks this PR since both are pre-existing spec-level scope decisions or are already substantively satisfied.