feat: add the research skill

A small, model-invoked skill that spins up a background agent to
investigate a question against high-trust primary sources, then leaves a
single cited Markdown file wherever the repo keeps such notes.

Wires it into the plugin set, both READMEs (Model-invoked), a docs page,
and the ask-matt router, per the repo's promoted-skill conventions.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.changeset/research-skill.md

@@ -0,0 +1,5 @@
+---
+"mattpocock-skills": minor
+---
+
+Add the **`research`** skill — a small, model-invoked skill that spins up a **background agent** to investigate a question against **primary sources** (official docs, source code, specs, first-party APIs), then leaves a single cited Markdown file wherever the repo keeps such notes. It's delegable reading legwork: you keep working while it reads, and get back a document to grill, plan, or design against. Listed in the top-level and Engineering READMEs (Model-invoked), added to `.claude-plugin/plugin.json`, given a docs page at `docs/engineering/research.md`, and routed as a Standalone in `ask-matt`.

.claude-plugin/plugin.json

@@ -11,6 +11,7 @@
     "./skills/engineering/to-issues",
     "./skills/engineering/to-prd",
     "./skills/engineering/prototype",
+    "./skills/engineering/research",
     "./skills/engineering/domain-modeling",
     "./skills/engineering/codebase-design",
     "./skills/engineering/code-review",

README.md

@@ -161,6 +161,7 @@ Skills I use daily for code work.
 
 - **[prototype](./skills/engineering/prototype/SKILL.md)** — Build a throwaway prototype to answer a design question — a runnable terminal app for state/logic questions, or several radically different UI variations toggleable from one route.
 - **[diagnosing-bugs](./skills/engineering/diagnosing-bugs/SKILL.md)** — Disciplined diagnosis loop for hard bugs and performance regressions: reproduce → minimise → hypothesise → instrument → fix → regression-test.
+- **[research](./skills/engineering/research/SKILL.md)** — Investigate a question against high-trust primary sources and capture the findings as a cited Markdown file in the repo, run as a background agent.
 - **[tdd](./skills/engineering/tdd/SKILL.md)** — Test-driven development with a red-green-refactor loop. Builds features or fixes bugs one vertical slice at a time.
 - **[domain-modeling](./skills/engineering/domain-modeling/SKILL.md)** — Actively build and sharpen a project's domain model — challenge terms against the glossary, stress-test with edge-case scenarios, and update `CONTEXT.md` and ADRs inline.
 - **[codebase-design](./skills/engineering/codebase-design/SKILL.md)** — Shared discipline and vocabulary for designing deep modules: a lot of behaviour behind a small interface, placed at a clean seam, testable through that interface.

docs/engineering/research.md

@@ -0,0 +1,29 @@
+Quickstart:
+
+```bash
+npx skills add mattpocock/skills --skill=research
+```
+
+```bash
+npx skills update research
+```
+
+[Source](https://github.com/mattpocock/skills/tree/main/skills/engineering/research)
+
+## What it does
+
+`research` answers a question by reading the sources that own the answer and leaving a cited Markdown file behind. It works only from **primary sources** — official docs, source code, specs, first-party APIs — never a secondary write-up of them, so what it saves is traceable back to something authoritative rather than a summary of a summary.
+
+## When to reach for it
+
+Type `/research`, or the agent reaches for it automatically when a task turns into reading legwork.
+
+Reach for it when the next step is *finding something out* — how an API behaves, what a spec actually says, whether a claim holds — and you'd rather not stall your own thread doing the reading. For sharpening a plan by interview instead of by reading, use [grilling](https://aihero.dev/skills-grilling); for exploring what to build with throwaway code, use [prototype](https://aihero.dev/skills-prototype).
+
+## Delegated legwork
+
+The defining move is that the reading runs as a **background agent**. You keep working; it goes off, follows each claim back to its primary source, and drops a single cited Markdown file into wherever the repo keeps such notes. Research is legwork you delegate, not thinking you outsource — you get back a document to react to, with its sources attached.
+
+## Where it fits
+
+A reach-for-it-anytime standalone that feeds the thinking skills: the file it produces is something to grill, plan, or design against, so it sits upstream of work like [grilling](https://aihero.dev/skills-grilling) and [to-prd](https://aihero.dev/skills-to-prd) rather than in the build chain. For the whole map, see [ask-matt](https://aihero.dev/skills-ask-matt).

skills/engineering/README.md

@@ -21,6 +21,7 @@ Model- or user-reachable (rich trigger phrasing so the model can reach for them)
 - **[prototype](./prototype/SKILL.md)** — Build a throwaway prototype to answer a design question: a runnable terminal app for state/logic, or several toggleable UI variations.
 
 - **[diagnosing-bugs](./diagnosing-bugs/SKILL.md)** — Disciplined diagnosis loop for hard bugs and performance regressions: reproduce → minimise → hypothesise → instrument → fix → regression-test.
+- **[research](./research/SKILL.md)** — Investigate a question against high-trust primary sources and capture the findings as a cited Markdown file in the repo, run as a background agent.
 - **[tdd](./tdd/SKILL.md)** — Test-driven development with a red-green-refactor loop. Builds features or fixes bugs one vertical slice at a time.
 - **[domain-modeling](./domain-modeling/SKILL.md)** — Actively build and sharpen a project's domain model — challenge terms, stress-test with scenarios, update `CONTEXT.md` and ADRs inline.
 - **[codebase-design](./codebase-design/SKILL.md)** — Shared discipline and vocabulary for designing deep modules: small interfaces, clean seams, testable through the interface.

skills/engineering/ask-matt/SKILL.md

@@ -65,6 +65,7 @@ Off the main flow entirely.
 
 - **`/grill-me`** — the same relentless interview as `/grill-with-docs`, but for when you have **no codebase**. Stateless: it saves nothing locally, builds no `CONTEXT.md`. Reach for it to sharpen any plan or design that doesn't live in a repo.
 - **`/prototype`** — a small, throwaway program that answers one design question: does this state model feel right, or what should this UI look like. Throwaway from day one — keep the answer, delete the code. It's the detour in step 2 of the main flow, but reach for it any time a design question is hard to settle on paper.
+- **`/research`** — delegate reading legwork to a **background agent**: it investigates a question against **primary sources**, then leaves a cited Markdown file in the repo. Keep working while it reads. The file it produces is something to take *into* the main flow at `/grill-with-docs` — research feeds the thinking, it doesn't replace it.
 - **`/teach`** — learn a concept over multiple sessions, using the current directory as a stateful workspace.
 - **`/writing-great-skills`** — reference for writing and editing skills well.
 

skills/engineering/research/SKILL.md

@@ -0,0 +1,12 @@
+---
+name: research
+description: Investigate a question against high-trust primary sources and capture the findings as a Markdown file in the repo. Use when the user wants a topic researched, docs or API facts gathered, or reading legwork delegated to a background agent.
+---
+
+Spin up a **background agent** to do the research, so you keep working while it reads.
+
+Its job:
+
+1. Investigate the question against **primary sources** — official docs, source code, specs, first-party APIs — not a secondary write-up of them. Follow every claim back to the source that owns it.
+2. Write the findings to a single Markdown file, citing each claim's source.
+3. Save it where the repo already keeps such notes; match the existing convention, and if there is none, put it somewhere sensible and say where.