gitea: provision a ci-bot account with repo + branch-protection access

Workflows push as a dedicated ci-bot account rather than a human one, so its
PAT can be scoped, rotated and revoked on its own. Adding a repo to
`ciBotRepos` and redeploying is all it takes to grant access.

Collaborator access and branch-protection push-whitelisting exist only on
gitea's HTTP API — no CLI, no config-file surface — so this one part stays
imperative: a oneshot that PUT/PATCHes the API into the desired state. It
runs on deploys where the script changed, which means it won't self-heal a
revert done through the web UI unless the unit is restarted too.

Two secrets, deliberately distinct:
- gitea_provisioning_token is darman's own token (write:repository +
  write:user). Only an owner-scoped token clears reqOwnerCheck on the
  collaborator and branch-protection endpoints, and write:user is what lets
  it write the Actions secret below. ci-bot cannot grant itself access.
- gitea_ci_bot_token is ci-bot's push token, generated once by hand (the
  command is in the comment) and pushed into gitea as a user-level Actions
  secret CI_BOT_TOKEN. Gitea has no instance-wide secret scope, and every
  repo here is owned by darman directly rather than an org, so a user-level
  secret is the closest thing — repo-level lookups fall back to it.

Branch protection is applied to the default branch plus `develop`, since
version-bump.yml pushes there.

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

services/dev/gitea.nix

@@ -1,4 +1,4 @@
-{ config, ... }:
+{ config, lib, pkgs, ... }:
 
 # Gitea — self-hosted git. stateDir/repositories were migrated from the old
 # ZimaOS docker instance straight into stateDir's default layout, so no
@@ -9,6 +9,12 @@
 # HTTP is reverse-proxied through Caddy (hosts/jupiter/configuration.nix).
 # SSH uses gitea's own built-in server on :2222 (not the host's :22, and not
 # :222 — the unpriv gitea user can't bind <1024).
+let
+  # Repos where the ci-bot account (see below) should be a Write collaborator
+  # and whitelisted to push past branch protection. Add a repo here and
+  # redeploy — no manual UI clicking needed.
+  ciBotRepos = [ "darman/hypr-chrome" ];
+in
 {
   services.gitea = {
     enable = true;
@@ -66,4 +72,98 @@
       "ubuntu-22.04:docker://ghcr.io/catthehacker/ubuntu:act-22.04"
     ];
   };
+
+  # ci-bot: dedicated account CI workflows push as (kept separate from any
+  # human account so its own PAT can be scoped/rotated/revoked independently).
+  # Collaborator access + branch-protection push-whitelisting have no CLI or
+  # config-file surface in gitea — only the HTTP API — so this is the one
+  # part of the setup that stays imperative even though it's nix-triggered:
+  # a oneshot that PUTs/PATCHes the API into the desired state on every
+  # deploy where its script changed (adding a repo to `ciBotRepos` and
+  # redeploying is enough to pick it up; it won't self-heal a manual revert
+  # done via the web UI unless the unit is also restarted).
+  #
+  # Auth for those API calls is darman's OWN token (named
+  # "jupiter-ci-bot-provisioning" in gitea, scopes write:repository +
+  # write:user — see hosts/jupiter/secrets.nix), since darman owns the repos
+  # in ciBotRepos and only an owner-scoped token clears the reqOwnerCheck on
+  # the collaborator/branch-protection endpoints; write:user is additionally
+  # needed to push ci-bot's token below as a secret on darman's own account.
+  # It is NOT ci-bot's own push token — ci-bot can't grant itself access.
+  #
+  # ci-bot's own push token (separate secret, ci_bot_token) is generated
+  # once via:
+  #   su gitea -s /bin/sh -c \
+  #     'GITEA_WORK_DIR=/mnt/data/AppData/gitea gitea admin user generate-access-token \
+  #      --username ci-bot --scopes write:repository'
+  # and this service pushes it into gitea itself as a user-level Actions
+  # secret (CI_BOT_TOKEN, on darman's account — see the PUT below) so
+  # workflows in ciBotRepos can push as ci-bot without a per-repo secret.
+  systemd.services.gitea-ci-bot-provision = {
+    description = "Provision ci-bot gitea account + repo access";
+    after = [ "gitea.service" ];
+    requires = [ "gitea.service" ];
+    wantedBy = [ "multi-user.target" ];
+    path = [ pkgs.curl pkgs.jq config.services.gitea.package ];
+    environment = {
+      TOKEN_FILE = config.sops.secrets.gitea_provisioning_token.path;
+      CI_BOT_TOKEN_FILE = config.sops.secrets.gitea_ci_bot_token.path;
+    };
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      User = config.services.gitea.user;
+    };
+    script = ''
+      set -euo pipefail
+      api=http://127.0.0.1:${toString config.services.gitea.settings.server.HTTP_PORT}/api/v1
+      admin_token="$(cat "$TOKEN_FILE")"
+      auth=(-H "Authorization: token $admin_token")
+
+      for _ in $(seq 1 30); do
+        curl -fs "$api/version" >/dev/null 2>&1 && break
+        sleep 1
+      done
+
+      if ! curl -fs "''${auth[@]}" "$api/users/ci-bot" >/dev/null 2>&1; then
+        GITEA_WORK_DIR=${config.services.gitea.stateDir} gitea admin user create \
+          --username ci-bot \
+          --email ci-bot@${config.services.gitea.settings.server.DOMAIN} \
+          --random-password --must-change-password=false
+      fi
+
+      # No instance-wide secret scope exists in Gitea (it's an open feature
+      # request) - a user-level secret on darman's own account is the closest
+      # equivalent, since every repo below is owned directly by darman, not
+      # an org, and repo-level secrets fall back to user-level when unset.
+      ci_bot_token="$(cat "$CI_BOT_TOKEN_FILE")"
+      curl -fsS "''${auth[@]}" -H 'Content-Type: application/json' \
+        -X PUT "$api/user/actions/secrets/CI_BOT_TOKEN" \
+        -d "$(jq -n --arg data "$ci_bot_token" '{data: $data}')"
+
+      ${lib.concatMapStringsSep "\n" (repo: ''
+        curl -fsS "''${auth[@]}" -H 'Content-Type: application/json' \
+          -X PUT "$api/repos/${repo}/collaborators/ci-bot" \
+          -d '{"permission":"write"}'
+
+        default_branch="$(curl -fs "''${auth[@]}" "$api/repos/${repo}" | jq -r .default_branch)"
+
+        # ci-bot needs push access on every branch a workflow might commit
+        # back to (currently just `develop`, where version-bump.yml pushes),
+        # in addition to whatever the repo's actual default branch is.
+        branches="$(printf '%s\n' "$default_branch" develop | sort -u)"
+        for branch in $branches; do
+          if curl -fs "''${auth[@]}" "$api/repos/${repo}/branch_protections/$branch" >/dev/null 2>&1; then
+            curl -fsS "''${auth[@]}" -H 'Content-Type: application/json' \
+              -X PATCH "$api/repos/${repo}/branch_protections/$branch" \
+              -d '{"enable_push":true,"enable_push_whitelist":true,"push_whitelist_usernames":["ci-bot"]}'
+          else
+            curl -fsS "''${auth[@]}" -H 'Content-Type: application/json' \
+              -X POST "$api/repos/${repo}/branch_protections" \
+              -d "{\"branch_name\":\"$branch\",\"enable_push\":true,\"enable_push_whitelist\":true,\"push_whitelist_usernames\":[\"ci-bot\"]}"
+          fi
+        done
+      '') ciBotRepos}
+    '';
+  };
 }