Add agent instructions bundle editing

Expose first-class instructions bundle APIs, preserve agent prompt bundles in portability flows, and replace the Agent Detail prompts tab with file-backed bundle editing while retiring bootstrap prompt UI.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/components/AgentConfigForm.tsx

@@ -735,36 +735,6 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
                     )}
                 </>
               )}
-              <Field label="Bootstrap prompt (first run)" hint={help.bootstrapPrompt}>
-                <MarkdownEditor
-                  value={
-                    isCreate
-                      ? val!.bootstrapPrompt
-                      : eff(
-                          "adapterConfig",
-                          "bootstrapPromptTemplate",
-                          String(config.bootstrapPromptTemplate ?? ""),
-                        )
-                  }
-                  onChange={(v) =>
-                    isCreate
-                      ? set!({ bootstrapPrompt: v })
-                      : mark("adapterConfig", "bootstrapPromptTemplate", v || undefined)
-                  }
-                  placeholder="Optional initial setup prompt for the first run"
-                  contentClassName="min-h-[44px] text-sm font-mono"
-                  imageUploadHandler={async (file) => {
-                    const namespace = isCreate
-                      ? "agents/drafts/bootstrap-prompt"
-                      : `agents/${props.agent.id}/bootstrap-prompt`;
-                    const asset = await uploadMarkdownImage.mutateAsync({ file, namespace });
-                    return asset.contentPath;
-                  }}
-                />
-              </Field>
-              <div className="rounded-md border border-sky-500/25 bg-sky-500/10 px-3 py-2 text-xs text-sky-100">
-                Bootstrap prompt is only sent for fresh sessions. Put stable setup, habits, and longer reusable guidance here. Frequent changes reduce the value of session reuse because new sessions must replay it.
-              </div>
               {adapterType === "claude_local" && (
                 <ClaudeLocalAdvancedFields {...adapterFieldProps} />
               )}