S8: main DRB bot optional end to end + owner-flow integration tests (server-26#225)

- Copy: picker, admin Servers/Streams/How-it-works, org Discord card, bot
  /help and the server-limit refusal no longer imply the DRB server bot is
  required; a radio bot alone is enough.
- Admin overview: per-server main_bot_present, radio_bots, linked_via,
  directory_source; Servers tab gets a Bots column.
- discord_web docstring: states the reversed "never calls Discord" rule
  (plan finding 5) and the optional server bot.
- Server bot directory cog: re-push (which drops C2's cached permission
  answers) on overwrite changes, role permission changes and role deletes.
- tests/test_discord_owner_flows.py: one-bot org (BYO bot, owner-set
  preferred, OAuth link, picker, start, reconciler) and full setup (server
  bot + 4 radio bots: placement, shared channel, every refusal explained),
  against a modelled Discord over httpx.MockTransport.
- storage.download_audio removed: no caller on main since #233.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-frontend/app/settings/discord/page.tsx

@@ -43,8 +43,8 @@ function Kpi({ k, v, s }: { k: string; v: string; s: string }) {
 
 function HowItWorks() {
   const steps = [
-    ["1 · Desired", "/join in Discord or this page writes a discord_streams doc."],
-    ["2 · Lease", "C2 picks an online node on that system and a radio bot already in that server, in one transaction."],
+    ["1 · Desired", "A node page's picker, this page, or /join (DRB server bot) writes a discord_streams doc."],
+    ["2 · Lease", "C2 picks an online node on that system and a radio bot already in that server that Discord lets View, Connect and Speak in the channel — the system's preferred bot first — in one transaction."],
     ["3 · Reconcile", "A retained MQTT message tells the node its full channel list (token ids, never token strings)."],
     ["4 · Voice", "The node logs in as the leased bot and plays its PulseAudio capture — never Icecast."],
     ["5 · Actual", "The node reports each channel's real state; this page and the Discord reply show it."],
@@ -54,6 +54,12 @@ function HowItWorks() {
       title="How a radio channel stays up"
       note="Node reboot, C2 sweep, Discord voice drop: the node re-reads its desired state and reconnects; persistent channels whose node went away are re-placed on another node. A channel desired-on but not connected for 2 minutes turns red on the Radio channels tab."
     >
+      <p className="px-4 pt-4 text-xs text-ink-2">
+        <b className="text-ink">The DRB server bot is optional.</b> One radio bot in a Discord server is enough: adding it
+        through <i>Connect a Discord server</i> (Settings → Organization) links the server, and C2 reads its voice
+        channels and permissions with that bot. The server bot adds the slash commands (/join, /leave, /status,
+        /drb link) and pushes its own channel list; both ways keep working side by side.
+      </p>
       <div className="grid gap-2 p-4 grid-cols-1 sm:grid-cols-2 lg:grid-cols-5">
         {steps.map(([t, d]) => (
           <div key={t} className="bg-raised border border-line rounded-lg p-3 text-xs text-ink-muted">

drb-frontend/components/DiscordServersCard.tsx

@@ -329,12 +329,13 @@ export function DiscordServersCard({ canEdit, isAdmin }: { canEdit: boolean; isA
 
       <div className="px-5 py-3 border-t border-line bg-raised text-xs text-ink-muted">
         {restricted ? (
-          <>Unlinked servers see only <b className="text-ink">/drb link</b> and <b className="text-ink">/help</b>. </>
+          <>Where the DRB server bot is present, an unlinked server sees only <b className="text-ink">/drb link</b> and <b className="text-ink">/help</b>. </>
         ) : isAdmin ? (
           <>Platform setting: unlinked servers still act for the default organization (<span className="font-mono">DISCORD_UNLINKED_GUILD_ORG_ID</span>) until linked. </>
         ) : null}
-        Every command and autocomplete is scoped to the linked organization — no server sees another
-        organization&apos;s nodes, systems or bots.
+        Radio channels, and every DRB server bot command and autocomplete, are scoped to the linked organization — no
+        server sees another organization&apos;s nodes, systems or bots. The DRB server bot is optional: a radio bot
+        alone is enough to stream.
       </div>
     </Card>
   );

drb-frontend/components/NodeDiscordRadio.tsx

@@ -2,9 +2,11 @@
 
 // Node page "Discord radio" panel + picker (server-26#213 item 3, #109 item 13).
 // Replaces the raw Guild ID / Voice Channel ID modal. The picker lists only
-// the Discord servers linked to this node's org and the voice channels the
-// DRB bot reported in them; a pick becomes a radio channel pinned to this node
-// (desired state — the node reconciles and reports back, shown per row).
+// the Discord servers linked to this node's org and their voice channels, as
+// read by a radio bot in the server or pushed by the DRB server bot — either
+// is enough; the server bot is optional (server-26#225). A pick becomes a
+// radio channel pinned to this node (desired state — the node reconciles and
+// reports back, shown per row).
 // A voice channel can carry several radio streams, each its own bot playing
 // its own system (server-26#213 follow-up): picking a channel that already
 // plays another system ADDS this node's system beside it; only a stream of
@@ -211,8 +213,9 @@ function DiscordPicker({
             <legend className="text-xs text-ink-muted mb-2">Discord server</legend>
             {usable.length === 0 ? (
               <p className="text-xs text-ink-2 bg-raised border border-line rounded-lg px-3 py-2">
-                No Discord server is linked to your organization yet. Add the DRB bot to your Discord server and
-                link it to your organization; it shows up here once the bot reports its channels.
+                No Discord server is linked to your organization yet. The organization owner connects one under
+                Settings → Organization → <b className="text-ink">Connect a Discord server</b>: adding a radio bot
+                to the server links it, and its voice channels show up here.
               </p>
             ) : (
               <div className="space-y-1.5">
@@ -259,12 +262,13 @@ function DiscordPicker({
               <legend className="text-xs text-ink-muted mb-2">Voice channel</legend>
               {!guild.synced ? (
                 <p className="text-xs text-ink-2 bg-raised border border-line rounded-lg px-3 py-2">
-                  The DRB bot has not reported this server&apos;s channels yet. It does when it starts and every 15
-                  minutes — check back shortly.
+                  DRB hasn&apos;t read this server&apos;s voice channels yet. A radio bot in the server lists them
+                  (or the DRB server bot, if it&apos;s there) — close this and open it again in a moment. If it
+                  stays empty, no radio bot is in this server yet — invite one with the link under the server above.
                 </p>
               ) : guild.voice_channels.length === 0 ? (
                 <p className="text-xs text-ink-2 bg-raised border border-line rounded-lg px-3 py-2">
-                  This server has no voice channels the DRB bot can see.
+                  This server has no voice channels DRB&apos;s bots can see.
                 </p>
               ) : (
                 <div className="space-y-2">

drb-frontend/components/discord/ServersPanel.tsx

@@ -8,8 +8,12 @@ import { DIM, Field, INPUT, Panel, Status, Table, TD } from "./ui";
 
 // Linked Discord servers = discord_guilds docs, plus any server that has had a
 // radio channel without being linked (it acts for DISCORD_UNLINKED_GUILD_ORG_ID).
-// Linking is PUT /discord/guilds/{id}/link (platform admin). The owner-side
-// "/drb link code:" flow is server-26#213 item 1 and is not built here.
+// Linking here is PUT /discord/guilds/{id}/link (platform admin, support).
+// Org owners link their own from Settings → Organization: "Connect a Discord
+// server" (a radio bot's OAuth invite, no DRB server bot needed) or a
+// /drb link code (needs the server bot) — server-26#213 item 1, #225.
+// The Bots column says which bots are in each server: the DRB server bot is
+// optional (server-26#225 S8), one radio bot is enough to stream.
 // Remove is DELETE /discord/guilds/{id}: its radio channels are stopped then
 // deleted, and the server is unlinked with no fallback org.
 
@@ -85,6 +89,30 @@ function LinkForm({
   );
 }
 
+// Which bots are in the server. The DRB server bot is optional (server-26#225):
+// "not there" is only a problem when no radio bot is either.
+function BotsCell({ guild }: { guild: DiscordGuild }) {
+  const radio = guild.radio_bots ?? [];
+  const main = guild.main_bot_present;
+  return (
+    <>
+      <div>
+        {radio.length > 0 ? (
+          <span title={radio.join(", ")}>
+            {radio.length} radio bot{radio.length === 1 ? "" : "s"}
+          </span>
+        ) : (
+          <span className={main ? DIM : "text-sev-moderate"}>no radio bot</span>
+        )}
+      </div>
+      <div className={DIM}>
+        DRB server bot: {main === true ? "present" : main === false ? "not there" : "never seen"}
+        {guild.directory_source === "radio_bot" && " · channels via radio bot"}
+      </div>
+    </>
+  );
+}
+
 type RemoveResult = { guild: string; streams: number; bots: { name: string; left: boolean; error: string | null }[] };
 
 function RemoveForm({
@@ -131,7 +159,7 @@ function RemoveForm({
         </span>
       </label>
       <p className="text-ink-muted">
-        The DRB bot itself stays in the Discord server until someone kicks it there.
+        The DRB server bot, if it is in the Discord server, stays until someone kicks it there.
       </p>
       {error && <p className="text-sev-major">{error}</p>}
       <div className="flex gap-2">
@@ -171,8 +199,9 @@ export function ServersPanel({
         fallback ? (
           <>
             <b className="text-ink">Unlinked servers act for {fallbackName}</b> (DISCORD_UNLINKED_GUILD_ORG_ID). Any
-            server the DRB bot is invited to can use that org&apos;s systems until it is linked here. Set the variable
-            to an empty string once every real server is linked.
+            server the DRB server bot is invited to can use that org&apos;s systems until it is linked here (a radio
+            bot alone never puts an unlinked server here). Set the variable to an empty string once every real server
+            is linked.
           </>
         ) : (
           <>Unlinked servers can&apos;t use radio commands until they are linked here.</>
@@ -189,14 +218,16 @@ export function ServersPanel({
               {removed.bots.map((b) => `${b.name} ${b.left ? "left" : `did not leave (${b.error ?? "unknown error"})`}`).join("; ")}.
             </>
           )}{" "}
-          The DRB bot is still in that Discord server until someone kicks it.
+          The DRB server bot, if it was there, stays in that Discord server until someone kicks it.
           <button className="ml-3 text-accent hover:underline" onClick={() => setRemoved(null)}>Dismiss</button>
         </div>
       )}
       {overview.guilds.length === 0 ? (
-        <p className="px-4 py-6 text-sm text-ink-muted">No Discord servers yet. Link one, or run a radio command in a server the DRB bot is in.</p>
+        <p className="px-4 py-6 text-sm text-ink-muted">
+          No Discord servers yet. Link one here, or an organization owner connects one under Settings → Organization.
+        </p>
       ) : (
-        <Table head={["Server", "Acts for", "Radio channels", "Linked", "Status", ""]}>
+        <Table head={["Server", "Acts for", "Bots", "Radio channels", "Linked", "Status", ""]}>
           {overview.guilds.flatMap((g) => {
             const row = (
               <tr key={g.guild_id}>
@@ -208,6 +239,9 @@ export function ServersPanel({
                   {g.acting_org_name || g.acting_org_id || <span className={DIM}>nobody</span>}
                   {!g.linked && g.acting_org_id && <div className={DIM}>fallback, not linked</div>}
                 </td>
+                <td className={TD}>
+                  <BotsCell guild={g} />
+                </td>
                 <td className={TD}>
                   {g.live_streams} / {max}
                 </td>
@@ -251,7 +285,7 @@ export function ServersPanel({
               return [
                 row,
                 <tr key={`${g.guild_id}-remove`}>
-                  <td colSpan={6} className="p-0 border-b border-line">
+                  <td colSpan={7} className="p-0 border-b border-line">
                     <RemoveForm
                       guild={g}
                       onCancel={() => setRemoving(null)}
@@ -269,7 +303,7 @@ export function ServersPanel({
             return [
               row,
               <tr key={`${g.guild_id}-edit`}>
-                <td colSpan={6} className="p-0 border-b border-line">
+                <td colSpan={7} className="p-0 border-b border-line">
                   <LinkForm overview={overview} guild={g} onDone={done} onCancel={() => setEditing(null)} />
                 </td>
               </tr>,

drb-frontend/components/discord/StreamsPanel.tsx

@@ -348,7 +348,8 @@ export function StreamsPanel({
       )}
       {overview.streams.length === 0 ? (
         <p className="px-4 py-6 text-sm text-ink-muted">
-          No radio channels yet. Start one here, or run <span className="font-mono">/join</span> in a linked Discord server.
+          No radio channels yet. Start one here or from a node&apos;s Discord radio panel, or run{" "}
+          <span className="font-mono">/join</span> where the DRB server bot is in a linked Discord server.
         </p>
       ) : (
         <Table head={["Server · channel", "Source", "Talkgroups", "Mode", "Desired → actual", "Bot", ""]}>

drb-frontend/lib/discord.ts

@@ -85,6 +85,14 @@ export interface DiscordGuild {
   acting_org_id: string | null;
   acting_org_name: string | null;
   live_streams: number;
+  /** How it was linked: "admin" | "code" | "oauth" (absent on older links). */
+  linked_via?: string | null;
+  /** The DRB server bot (optional, server-26#225): true/false as it last reported, null = never heard. */
+  main_bot_present?: boolean | null;
+  /** Who listed its voice channels: "main_bot" | "radio_bot". */
+  directory_source?: string | null;
+  /** Radio bots Discord last said are in this server (names). */
+  radio_bots?: string[];
 }
 
 export interface DiscordAdminOverview {