docs: add TODO.md backlog and link from docs index

Captures unscoped forward-looking items (peering/federation model,
distributed git & OTA, nostr integration, platform/OS, app testing,
observability, and the dev/build process) so they're tracked outside
of ROADMAP.md's curated public summary.

docs/README.md

@@ -86,4 +86,5 @@ file.
 ## Roadmap & history
 
 - [Roadmap](ROADMAP.md) — where the project is going
+- [TODO](TODO.md) — working backlog of unscoped forward-looking items
 - [archive/](archive/README.md) — superseded design and status documents, kept for provenance

docs/TODO.md

@@ -0,0 +1,42 @@
+# TODO
+
+Working backlog of forward-looking items not yet scoped into a dedicated plan
+doc. See [`ROADMAP.md`](ROADMAP.md) for the curated, public-facing direction.
+
+## Dev & build process (priority)
+
+- Formalize the contributor workflow: releases, CI, maintainers, automated
+  builds, PR/issue flow, branch naming, and reproducible builds.
+
+## Federation & peering
+
+- Peering trust model — define tiers (trusted / public / private / peered)
+  on top of the existing federation DID trust levels.
+- Federation architecture built on the above peering model.
+
+## Distributed git & OTA
+
+- Nostr-hosted git for the alpha (see
+  [`nostr-git-source-hosting.md`](nostr-git-source-hosting.md)).
+- Distributed git beyond the nostr-hosting case.
+- Distributed OTA / app delivery.
+
+## Nostr integration
+
+- Nostr signer integration.
+
+## Platform / OS
+
+- Source-availability ISO — define the build/distribution story.
+- HW/OS update pipeline.
+- Deeper OpenWRT integration.
+- GrapheneOS integration — backups, attestation, profiles.
+
+## App ecosystem
+
+- Full pass testing every app in the catalog; expect issues across the board.
+
+## Observability
+
+- Capture error logs to troubleshoot customer issues.
+- Stats & visualization for traffic, blocked attacks, VPNs, routing.