Give bots skills: runbooks they load when a job matches

A skill is a runbook: a name, a unique slug, a one-line description of when
it applies, and the markdown body. A run only ever sees the slug and
description (one load_skill tool carries them), and reads the whole body
only when it calls the tool, so a long runbook costs nothing until needed.

Skills are the third extension kind beside MCP servers and custom tools, on
the same botExtensionsSql path, so per-bot, per-workspace and all-bots
grants work the same way, and attachDefaultExtensions hands an every-bot
skill to new bots. load_skill is a reserved tool name, so a custom tool
cannot shadow it, and a built-in wins a clash.

Managed on Settings > Skills; ExtensionRow links each kind to its own page
and a skill never reports a failure, since nothing connects or runs.

src/pages/admin/bots/[bot_id]/(partials)/composer-tool-row.tsx

@@ -17,8 +17,9 @@ type Props = {
 };
 
 /**
- * One MCP server or tool the bot can use here, in the composer's tools
- * modal. One that isn't working says so, one that's off is struck out.
+ * One MCP server, tool or skill the bot can use here, in the composer's
+ * tools modal. One that isn't working says so, one that's off is struck
+ * out. A skill has nothing to connect or run, so it never reports one.
  */
 export default function ComposerToolRow({ item, busy, onRemove }: Props) {
     const Icon = extensionIcon({ kind: item.kind });
@@ -27,11 +28,13 @@ export default function ComposerToolRow({ item, busy, onRemove }: Props) {
         item.source == "workspace" ? "From this workspace" : "",
         !item.enabled
             ? "Off for every bot"
-            : item.state == "error"
-              ? "Not working"
-              : item.state == "untested"
-                ? "Not checked yet"
-                : "",
+            : item.kind == "skill"
+              ? ""
+              : item.state == "error"
+                ? "Not working"
+                : item.state == "untested"
+                  ? "Not checked yet"
+                  : "",
     ].filter(Boolean);
 
     return (

src/pages/admin/bots/[bot_id]/(partials)/composer-tools-modal.tsx

@@ -18,19 +18,19 @@ type Props = {
      * The extension being changed, as `kind:id`.
      */
     busy?: string;
-    onAdd: (params: { kind: "mcp" | "tool"; id: number }) => Promise<boolean>;
+    onAdd: (params: { kind: "mcp" | "tool" | "skill"; id: number }) => Promise<boolean>;
     onRemove: (params: {
-        kind: "mcp" | "tool";
+        kind: "mcp" | "tool" | "skill";
         id: number;
         name: string;
     }) => Promise<boolean>;
 };
 
 /**
- * The composer's tools button: how many MCP servers and tools the bot can
- * use here, opening them in a modal rather than filling the composer with
- * chips. Super admins and admins remove any it was given (even one every
- * bot started with) and add more; a workspace's own stay.
+ * The composer's tools button: how many MCP servers, tools and skills the
+ * bot can use here, opening them in a modal rather than filling the
+ * composer with chips. Super admins and admins remove any it was given
+ * (even one every bot started with) and add more; a workspace's own stay.
  */
 export default function ComposerToolsModal({
     bot_name,
@@ -75,8 +75,8 @@ export default function ComposerToolsModal({
                 </H2>
                 <Span className="text-[13px] leading-[18px] text-ink-secondary">
                     {count
-                        ? "MCP servers and tools it was given, plus this workspace's. Remove one to take it away, or add another below."
-                        : "It has none yet. Give it an MCP server or tool below, or make one under Settings."}
+                        ? "MCP servers, tools and skills it was given, plus this workspace's. Remove one to take it away, or add another below."
+                        : "It has none yet. Give it an MCP server, tool or skill below, or make one under Settings."}
                 </Span>
             </Stack>
 

src/pages/admin/bots/[bot_id]/(partials)/composer-tools.tsx

@@ -15,7 +15,7 @@ type Props = {
 };
 
 /**
- * Under the composer: one button counting the MCP servers and tools the
+ * Under the composer: one button counting the MCP servers, tools and skills the
  * bot can use here (they open in a modal, so ten of them don't fill the
  * composer), then the computer it's on, opening it in the viewer.
  */

src/pages/admin/bots/[bot_id]/(partials)/composer.tsx

@@ -51,7 +51,7 @@ type Props = {
      */
     workspace_id?: number | null;
     /**
-     * Its MCP servers and tools, listed under the input.
+     * Its MCP servers, tools and skills, listed under the input.
      */
     extensions?: BotExtensionsPayload | null;
     /**