Prepare for public release: de-identify docs, add contributor terms

Removes personal infra baked into copy-paste instructions and the
app's own UI ahead of an eventual public release:

- AboutModal's "Source code" link is now a build-time env var
  (VITE_SOURCE_URL) instead of a hardcoded personal Gitea URL, and
  hides itself when unset rather than pointing somewhere wrong
- DEPLOYMENT.md's clone steps are genericized to any git host
- LICENSE gets its previously-blank copyright/description lines filled in
- CONTRIBUTING.md adds a lightweight contributor-terms note to keep a
  future dual-licensed offering possible once outside PRs start arriving

Deliberately out of scope for now: git commit history (still under the
real author identity) and the actual publish destination -- both still
undecided.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -0,0 +1,51 @@
+# Contributing to DS Chat
+
+Thanks for considering a contribution.
+
+## Reporting bugs and requesting features
+
+Open an issue on this project's issue tracker. Include steps to reproduce
+for a bug, or the problem you're trying to solve for a feature request —
+that's usually more useful than a proposed solution.
+
+## Development setup
+
+See the root [README.md](README.md)'s Quickstart, plus
+[backend/README.md](backend/README.md) and
+[frontend/README.md](frontend/README.md) for the full local dev setup
+(Postgres, Redis, Python venv, migrations, the Vite dev server).
+[ARCHITECTURE.md](ARCHITECTURE.md) covers the overall system design if
+you're orienting yourself before a larger change.
+
+## Before opening a pull request
+
+- **Tests**: run `pytest` in `backend/` for any backend change, and add
+  tests for new behavior rather than just the happy path — see
+  `backend/README.md`'s "Run tests" section. For frontend changes, run
+  `npx tsc -b` in `frontend/` and confirm `npm run build` succeeds.
+- **Style**: match the conventions already in the file you're editing
+  rather than introducing a new pattern — this codebase doesn't have a
+  separate style guide beyond "look at what's already there."
+- **Scope**: smaller, focused PRs are easier to review than large ones
+  that mix unrelated changes.
+
+## Contributor terms
+
+By submitting a contribution (a pull request, patch, or similar), you
+agree that:
+
+1. Your contribution is licensed under the project's own license,
+   AGPL-3.0-or-later ([LICENSE](LICENSE)), and
+2. You grant the project's maintainer(s) a perpetual, worldwide,
+   non-exclusive right to also relicense your contribution under different
+   terms — for example, as part of a separately-licensed commercial
+   offering built on this project.
+
+This keeps the option of a future dual-licensed (open-source +
+commercial) version of the project available, without requiring a
+separate signed agreement for every contribution.
+
+*This is a lightweight starting point, not a substitute for legal advice —
+if you're contributing something substantial, or maintaining a fork with
+your own commercial plans, it's worth having this reviewed by a lawyer
+rather than relying on the paragraph above alone.*

DEPLOYMENT.md

@@ -132,15 +132,16 @@ sudo -u ds-chat ssh-keygen -t ed25519 -f /srv/ds-chat/.ssh/id_ed25519 -N ""
 sudo cat /srv/ds-chat/.ssh/id_ed25519.pub
 ```
 
-Add that public key as a **read-only deploy key** on the Gitea repo
+Add that public key as a **read-only deploy key** in your git host's repo
-(Settings → Deploy Keys), then:
+settings (deploy keys are supported by GitHub, GitLab, Gitea, and most
+others — look for "Deploy Keys" under the repo's Settings), then:
 
 ```bash
-sudo -u ds-chat ssh-keyscan git.darksingularity.org >> /srv/ds-chat/.ssh/known_hosts
+sudo -u ds-chat ssh-keyscan <YOUR_GIT_HOST> >> /srv/ds-chat/.ssh/known_hosts
-sudo -u ds-chat git clone git@git.darksingularity.org:DarkSingularity/ds-chat.git /srv/ds-chat
+sudo -u ds-chat git clone git@<YOUR_GIT_HOST>:<YOUR_ORG>/ds-chat.git /srv/ds-chat
 ```
 
-(If your Gitea's SSH is on a non-default port, adjust the clone URL and
+(If your git host's SSH is on a non-default port, adjust the clone URL and
 `ssh-keyscan -p <port>` accordingly.)
 
 **Alternative: a personal/deployment-user access token instead of a deploy
@@ -148,7 +149,7 @@ key** — skip the `.ssh`/`ssh-keygen`/`ssh-keyscan` commands above entirely
 and clone over HTTPS with the token embedded in the URL:
 
 ```bash
-sudo -u ds-chat git clone https://<TOKEN>@git.darksingularity.org/DarkSingularity/ds-chat.git /srv/ds-chat
+sudo -u ds-chat git clone https://<TOKEN>@<YOUR_GIT_HOST>/<YOUR_ORG>/ds-chat.git /srv/ds-chat
 ```
 
 The token then lives in plaintext in `/srv/ds-chat/.git/config` (`git
@@ -232,7 +233,16 @@ admin sets it up.
 `/ws`) whenever that directory exists — that's what lets Nginx Proxy
 Manager forward the whole domain to one port with no custom path routing.
 
+Before building, copy `frontend/.env.example` to `frontend/.env.production`
+and set `VITE_SOURCE_URL` to wherever *your* copy of the repo lives — see
+that file's own comment for why this matters (AGPL-3.0 source-availability
+compliance). Vite bakes this in at build time, so it needs to be in place
+before `npm run build` runs, and needs re-running after any future change
+to it.
+
 ```bash
+sudo -u ds-chat cp /srv/ds-chat/frontend/.env.example /srv/ds-chat/frontend/.env.production
+sudo -u ds-chat nano /srv/ds-chat/frontend/.env.production  # set VITE_SOURCE_URL
 sudo -u ds-chat bash -c 'cd /srv/ds-chat/frontend && npm ci && npm run build'
 ```
 

LICENSE

@@ -629,8 +629,8 @@ to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
 
-    <one line to give the program's name and a brief idea of what it does.>
+    DS Chat, a self-hosted, real-time team chat service.
-    Copyright (C) <year>  <name of author>
+    Copyright (C) 2026  Keith Smith
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU Affero General Public License as published by

frontend/.env.example

@@ -0,0 +1,6 @@
+# Shown as the "Source code" link in the app's About screen -- required
+# for AGPL-3.0 section 13 compliance once you deploy this (a link so users
+# interacting with the app over the network can get the actual source,
+# including any modifications you've made). Point this at wherever *your*
+# copy of the repo actually lives, not the upstream project.
+VITE_SOURCE_URL=https://example.com/your-org/ds-chat

frontend/README.md

@@ -112,7 +112,7 @@ src/
     LoginPage.tsx, SignupPage.tsx, ForgotPasswordPage.tsx, ResetPasswordPage.tsx
     ChatShellPage.tsx, AdminPage.tsx, HelpPage.tsx
 
-  styles/tokens.css          design tokens (DarkSingularity theme: colors, spacing, etc.)
+  styles/tokens.css          design tokens (default theme: colors, spacing, etc.)
   sw.ts                      custom service worker (injectManifest): app-shell
                                precache + NetworkFirst runtime caching, push/notificationclick
                                handlers, SKIP_WAITING messaging for the update-prompt flow

frontend/src/components/AboutModal.tsx

@@ -10,8 +10,10 @@ interface AboutModalProps {
 // users remotely through a computer network, you should also make sure
 // that it provides a way for users to get its source... its interface
 // could display a 'Source' link" -- this modal is that link, not just a
-// courtesy credits screen.
+// courtesy credits screen. Deliberately not a hardcoded URL: whoever
-const SOURCE_URL = 'https://git.darksingularity.org/DarkSingularity/ds-chat'
+// deploys this needs to point it at *their* copy of the repo (including
+// any modifications), not the upstream project -- see frontend/.env.example.
+const SOURCE_URL = import.meta.env.VITE_SOURCE_URL as string | undefined
 
 export function AboutModal({ onClose }: AboutModalProps) {
   return (
@@ -39,11 +41,13 @@ export function AboutModal({ onClose }: AboutModalProps) {
           </a>
           .
         </p>
+        {SOURCE_URL && (
           <p className="about-modal-line">
             <a href={SOURCE_URL} target="_blank" rel="noopener noreferrer">
               Source code
             </a>
           </p>
+        )}
 
         <div className="modal-actions" style={{ marginTop: '1rem' }}>
           <button type="button" className="btn-secondary" onClick={onClose}>