Add top-level AGENTS.md

Amolith created 

Non-discoverable repo conventions: commands, REUSE licensing
requirements, and VCS/commit style expectations.

Change summary

AGENTS.md         | 24 ++++++++++++++++++++++++
AGENTS.md.license |  3 +++
2 files changed, 27 insertions(+)

Detailed changes

AGENTS.md 🔗 

@@ -0,0 +1,24 @@
+# AGENTS.md
+
+## Commands
+
+```sh
+bun install              # install deps (run after cloning)
+mise run check           # fmt + lint + typecheck
+mise run fmt             # biome format
+mise run lint            # biome lint
+mise run typecheck       # tsc --noEmit across all packages
+```
+
+## Licensing
+
+This repo uses REUSE. Every file needs SPDX headers or a `.license` sidecar.
+Run `reuse lint` to verify. Each package has its own license — check the
+existing headers before adding files.
+
+## VCS
+
+This is a jj repo. Use kernel-style commit messages (imperative, 50-char
+subject, body explains what/why). Use the format script at
+`~/.config/agents/skills/formatting-commits/scripts/format` to validate
+subjects and reflow bodies.

AGENTS.md.license 🔗 

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: Amolith <amolith@secluded.site>
+
+SPDX-License-Identifier: CC0-1.0