phase 0: project bootstrap

P0-01 Go module + cmd/server + cmd/agent skeletons + internal/ tree
P0-02 LICENSE (PolyForm NC 1.0.0), README, CONTRIBUTING
P0-03 golangci-lint, pre-commit, .editorconfig, .gitignore
P0-04 Gitea Actions CI: test (race+coverage), lint, cross-platform build matrix
P0-05 Dockerfile.server (multi-stage, distroless/static), docker-compose.yml
P0-06 Makefile with build/test/lint/fmt/run/release targets

build, vet, test, and cross-compile to linux/{amd64,arm64} + windows/amd64
all verified locally.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CONTRIBUTING.md

@@ -0,0 +1,30 @@
+# Contributing
+
+Thanks for your interest in contributing to restic-manager.
+
+> This is a placeholder. The project is in pre-alpha (Phase 1 / MVP). A
+> full contributor guide will land alongside the Phase 5 OSS-readiness
+> work — see [`tasks.md`](./tasks.md) P5-02. Until then the notes below
+> apply.
+
+## Before opening a PR
+
+1. Open an issue first for non-trivial changes — the design is still
+   moving (see [`spec.md`](./spec.md)) and unsolicited large PRs may
+   conflict with in-flight work.
+2. `make lint test` should pass.
+3. Match the existing code style — `gofumpt`, `goimports`, no comments
+   that just restate what the code does.
+4. Keep commits focused; one logical change per commit.
+
+## Reporting security issues
+
+Please do **not** open a public issue for security problems. A
+`SECURITY.md` with a private disclosure path will be added in Phase 5
+(P5-05). Until then, contact the repository owner directly via the
+contact details on their gitea profile.
+
+## License
+
+By contributing you agree that your contributions are licensed under
+the [PolyForm Noncommercial 1.0.0](./LICENSE) license.