chore: standardize repo with RSR dotfiles and SCM files

Added/updated:
- .editorconfig
- .tool-versions
- .meta/REQUIRED-FILES.md

🤖 Generated with [Claude Code](https://claude.ai/code)

Author: Jonathan D.A. Jewell

.editorconfig

@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.adoc]
+trim_trailing_whitespace = false
+
+[*.rs]
+indent_size = 4
+
+[*.zig]
+indent_size = 4
+
+[*.ada]
+indent_size = 3
+
+[*.adb]
+indent_size = 3
+
+[*.ads]
+indent_size = 3
+
+[*.ex]
+indent_size = 2
+
+[*.exs]
+indent_size = 2
+
+[*.hs]
+indent_size = 2
+
+[*.res]
+indent_size = 2
+
+[*.resi]
+indent_size = 2
+
+[*.ncl]
+indent_size = 2
+
+[*.scm]
+indent_size = 2
+
+[*.nix]
+indent_size = 2
+
+[Justfile]
+indent_style = space
+indent_size = 4
+
+[justfile]
+indent_style = space
+indent_size = 4
+
+[Makefile]
+indent_style = tab

.meta/REQUIRED-FILES.md

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+# Required Repository Files
+
+The following files **MUST** be present and kept up-to-date in every repository:
+
+## Mandatory Dotfiles
+
+| File | Purpose |
+|------|---------|
+| `.gitignore` | Exclude build artifacts, secrets, and temp files |
+| `.gitattributes` | Enforce LF line endings and diff settings |
+| `.editorconfig` | Consistent editor settings across IDEs |
+| `.tool-versions` | asdf version pinning for reproducible builds |
+
+## Mandatory SCM Files
+
+| File | Purpose |
+|------|---------|
+| `META.scm` | Architecture decisions, development practices |
+| `STATE.scm` | Project state, phase, milestones |
+| `ECOSYSTEM.scm` | Ecosystem positioning, related projects |
+| `PLAYBOOK.scm` | Executable plans, procedures |
+| `AGENTIC.scm` | AI agent operational gating |
+| `NEUROSYM.scm` | Symbolic semantics, proof obligations |
+
+## Build System
+
+| File | Purpose |
+|------|---------|
+| `justfile` | Task runner (replaces Makefile) |
+| `Mustfile` | Deployment state contract |
+
+**IMPORTANT**: Makefiles are FORBIDDEN. Use `just` for all tasks.
+
+## Validation
+
+These files are checked by:
+- CI workflow validation
+- Pre-commit hooks (when configured)
+- Repository standardization scripts
+
+## Updates
+
+When updating these files:
+1. Use templates from `rsr-template-repo` as reference
+2. Ensure SPDX license header is present
+3. Test changes locally before pushing
+4. Keep language-specific sections relevant to the repo
+
+## See Also
+
+- [RSR (Rhodium Standard Repositories)](https://github.com/hyperpolymath/rhodium-standard-repositories)
+- [Mustfile Specification](https://github.com/hyperpolymath/mustfile)
+- [SCM Format Family](https://github.com/hyperpolymath/meta-scm)

.tool-versions

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# asdf version management
+# Run 'asdf install' to install all tools
+
+# Primary runtime
+deno 2.1.4
+
+# Build tools
+just 1.36.0