Standardized organization repository guidance

AGENTS.md

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+# Repository instructions
+
+Read `README.md` for the repository's purpose and supported behavior. Read `CONTRIBUTING.md`
+before changing anything for development setup, architecture constraints, validation, and release
+requirements.
+
+Keep durable repository guidance in those files. Keep this file as a thin pointer so every
+contributor follows the same documentation.

CONTRIBUTING.md

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+# Contributing to Open Lobotomy organization defaults
+
+This repository controls shared GitHub behavior. A small edit can affect every repository that
+inherits a file or calls a reusable workflow, so verify the callers before changing the contract.
+
+## Repository structure
+
+- `.github/workflows/ci.yml` validates this repository's workflow files with `actionlint`.
+- `.github/workflows/dotnet-ci.yml` restores the consuming repository's local tools and runs
+  `dotnet ci --check` on Linux.
+- `.github/workflows/dotnet-ci-windows.yml` restores, builds, and tests the caller's requested
+  solution on Windows.
+- `profile/README.md` is the organization landing page.
+- `renovate.json` is the shared Renovate preset.
+
+There is no application code in this repository.
+
+## Reusable workflow contracts
+
+A caller references a workflow by repository path and branch:
+
+```yaml
+jobs:
+  ci:
+    uses: open-lobotomy/.github/.github/workflows/dotnet-ci.yml@main
+```
+
+Treat each `workflow_call` input, secret, default, output, permission, and job dependency as a public
+interface. Search the organization for every caller before renaming or removing one. Additive inputs
+need safe defaults so existing callers keep working.
+
+The Linux workflow accepts optional private-reference and local-package inputs. The Windows workflow
+also requires `solution-file`. Keep secret access scoped to the step that needs it, and never print a
+token or a generated NuGet source containing credentials.
+
+## GitHub inheritance
+
+GitHub inherits supported community files from this repository only when a child repository does not
+define its own copy. Inheritance is all or nothing per file. Before adding or changing an organization
+default, inspect the repositories that inherit it and the repositories that intentionally override it.
+
+## Validation
+
+Run `actionlint` against every workflow change. The repository CI downloads the current `actionlint`
+release and runs it from the repository root.
+
+Also perform the validation that matches the change:
+
+- Search all Open Lobotomy callers when a reusable workflow interface changes.
+- Check both Linux and Windows shell syntax when a shared step moves between runners.
+- Resolve every relative Markdown link when changing the profile or community documentation.
+- Validate `renovate.json` as JSON and compare it with at least one consuming repository before
+  changing inherited behavior.
+
+## Pull requests
+
+Branch from `main`, keep organization-wide changes narrow, and explain which repositories inherit or
+call the changed surface. A reusable workflow change is not complete until at least one representative
+consumer passes with the new contract.

README.md

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-# .github
-Temporary holding spot for workflows until our full public reveal.
+# Open Lobotomy organization defaults
+
+Shared GitHub configuration for the
+[Open Lobotomy organization](https://github.com/open-lobotomy). GitHub uses this repository for
+the organization profile and for reusable workflows that individual projects call from their own
+CI pipelines.
+
+## What lives here
+
+- `.github/workflows/dotnet-ci.yml` runs the standard Linux `dotnet ci --check` workflow.
+- `.github/workflows/dotnet-ci-windows.yml` restores, builds, and tests a named solution on Windows.
+- `profile/README.md` renders on the organization's public GitHub profile.
+- `renovate.json` provides the organization Renovate preset.
+
+Repository-local community files take precedence over organization defaults. GitHub replaces an
+inherited file as a whole, so a project-specific `CONTRIBUTING.md` does not merge with a file from
+this repository.
+
+Read [CONTRIBUTING.md](CONTRIBUTING.md) before changing a reusable workflow or an organization-wide
+default.