2 files changed, 407 insertions, 0 deletions
diff --git a/src/features/plugins/adapter/http.test.ts b/src/features/plugins/adapter/http.test.ts
new file mode 100644
index 0000000..b1fe477
--- /dev/null
+++ b/src/features/plugins/adapter/http.test.ts
@@ -0,0 +1,177 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createPluginsHttp } from "./http";
+
+/** A stub fetch that records requests and replies from a handler. */
+function stubFetch(handler: (url: string, init?: RequestInit) => Response | Promise<Response>) {
+  const impl = vi.fn(async (input: string | URL | Request, init?: RequestInit) => {
+    const url = typeof input === "string" ? input : input instanceof URL ? input.href : input.url;
+    return await handler(url, init);
+  });
+  return impl as unknown as typeof fetch;
+}
+
+const okJson = (body: unknown): Response =>
+  ({ ok: true, status: 200, json: async () => body }) as unknown as Response;
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+describe("createPluginsHttp — manager routes (plan 05)", () => {
+  it("GET /plugins returns the parsed list (null on failure)", async () => {
+    const fetch1 = stubFetch(() =>
+      okJson({ loaded: [], disabledWithReason: [], discovered: [], missing: [] }),
+    );
+    const http = createPluginsHttp("http://x", fetch1);
+    await expect(http.list()).resolves.toEqual({
+      loaded: [],
+      disabledWithReason: [],
+      discovered: [],
+      missing: [],
+    });
+
+    const fetch2 = stubFetch(() => ({ ok: false, status: 503 }) as unknown as Response);
+    await expect(createPluginsHttp("http://x", fetch2).list()).resolves.toBeNull();
+  });
+
+  it("POST /plugins/scan posts to the scan route", async () => {
+    let seenUrl = "";
+    let seenInit: RequestInit | undefined;
+    const fetch1 = stubFetch((url, init) => {
+      seenUrl = url;
+      seenInit = init;
+      return okJson({ root: "/plugins", newPlugins: [], invalid: [], incompatible: [] });
+    });
+    const http = createPluginsHttp("http://x", fetch1);
+    const result = await http.scan();
+    expect(result.ok).toBe(true);
+    expect(seenUrl).toBe("http://x/plugins/scan");
+    expect(seenInit?.method).toBe("POST");
+  });
+
+  it("POST /plugins/:id/unload sends the force flag in the body", async () => {
+    let seenBody: string | undefined;
+    const fetch1 = stubFetch((_url, init) => {
+      seenBody = init?.body as string;
+      return okJson({ ok: true, action: "unload", id: "mcp" });
+    });
+    const http = createPluginsHttp("http://x", fetch1);
+    await http.unload("mcp", true);
+    expect(JSON.parse(seenBody ?? "{}")).toEqual({ force: true });
+  });
+
+  it("maps a blocked mutation (409) to ok:false with reason + dependents", async () => {
+    const fetch1 = stubFetch(
+      () =>
+        ({
+          ok: false,
+          status: 409,
+          json: async () => ({
+            ok: false,
+            action: "unload",
+            id: "heartbeat",
+            reason: "cascade-needs-force",
+            message: "blocked",
+            dependents: ["transport-http"],
+          }),
+        }) as unknown as Response,
+    );
+    const http = createPluginsHttp("http://x", fetch1);
+    const result = await http.unload("heartbeat", false);
+    expect(result).toEqual({
+      ok: false,
+      error: "blocked",
+      reason: "cascade-needs-force",
+      dependents: ["transport-http"],
+    });
+  });
+
+  it("load and reload hit their routes with the encoded id", async () => {
+    const urls: string[] = [];
+    const fetch1 = stubFetch((url) => {
+      urls.push(url);
+      return okJson({ ok: true, action: "load", id: "a/b" });
+    });
+    const http = createPluginsHttp("http://x", fetch1);
+    await http.load("a/b");
+    await http.reload("a/b");
+    expect(urls).toEqual(["http://x/plugins/a%2Fb/load", "http://x/plugins/a%2Fb/reload"]);
+  });
+});
+
+describe("createPluginsHttp — workspace routes (plan 06 §6.6)", () => {
+  it("GET /workspaces/:id/plugins returns the parsed response (null on failure)", async () => {
+    const fetch1 = stubFetch(() =>
+      okJson({ workspaceId: "ws", plugins: [], enabledProviderCount: 2 }),
+    );
+    const http = createPluginsHttp("http://x", fetch1);
+    await expect(http.workspacePlugins("ws")).resolves.toEqual({
+      workspaceId: "ws",
+      plugins: [],
+      enabledProviderCount: 2,
+    });
+
+    const fetch2 = stubFetch(() => ({ ok: false, status: 503 }) as unknown as Response);
+    await expect(createPluginsHttp("http://x", fetch2).workspacePlugins("ws")).resolves.toBeNull();
+  });
+
+  it("PUT /workspaces/:id/plugins/:pluginId sends the state body", async () => {
+    let seenUrl = "";
+    let seenBody: string | undefined;
+    const fetch1 = stubFetch((url, init) => {
+      seenUrl = url;
+      seenBody = init?.body as string;
+      return okJson({ workspaceId: "ws", pluginId: "mcp", state: "enabled" });
+    });
+    const http = createPluginsHttp("http://x", fetch1);
+    const result = await http.setWorkspaceState("ws", "mcp", "enabled");
+    expect(result.ok).toBe(true);
+    expect(seenUrl).toBe("http://x/workspaces/ws/plugins/mcp");
+    expect(JSON.parse(seenBody ?? "{}")).toEqual({ state: "enabled" });
+  });
+
+  it("maps a 409 refusal (core-locked) to ok:false with the reason", async () => {
+    const fetch1 = stubFetch(
+      () =>
+        ({
+          ok: false,
+          status: 409,
+          json: async () => ({
+            workspaceId: "ws",
+            pluginId: "kernel",
+            reason: "core-locked",
+            message: "core is locked",
+          }),
+        }) as unknown as Response,
+    );
+    const http = createPluginsHttp("http://x", fetch1);
+    const result = await http.setWorkspaceState("ws", "kernel", "disabled");
+    expect(result).toEqual({ ok: false, error: "core is locked", reason: "core-locked" });
+  });
+
+  it("GET providers-status returns the parsed response", async () => {
+    let seenUrl = "";
+    const fetch1 = stubFetch((url) => {
+      seenUrl = url;
+      return okJson({ workspaceId: "ws", enabledProviderCount: 0 });
+    });
+    const http = createPluginsHttp("http://x", fetch1);
+    await expect(http.providersStatus("ws")).resolves.toEqual({
+      workspaceId: "ws",
+      enabledProviderCount: 0,
+    });
+    expect(seenUrl).toBe("http://x/workspaces/ws/plugins/providers-status");
+  });
+
+  it("network throws degrade reads to null and mutations to ok:false", async () => {
+    const boom = vi.fn(async () => {
+      throw new Error("down");
+    }) as unknown as typeof fetch;
+    const http = createPluginsHttp("http://x", boom);
+    await expect(http.list()).resolves.toBeNull();
+    await expect(http.providersStatus("ws")).resolves.toBeNull();
+    await expect(http.setWorkspaceState("ws", "mcp", "enabled")).resolves.toMatchObject({
+      ok: false,
+    });
+  });
+});
diff --git a/src/features/plugins/adapter/http.ts b/src/features/plugins/adapter/http.ts
new file mode 100644
index 0000000..7814f4f
--- /dev/null
+++ b/src/features/plugins/adapter/http.ts
@@ -0,0 +1,230 @@
+import type {
+  PluginListResponse,
+  PluginOpResponse,
+  PluginScanResponse,
+  SetWorkspacePluginStateBlocked,
+  SetWorkspacePluginStateRequest,
+  SetWorkspacePluginStateResponse,
+  WorkspacePluginProvidersStatusResponse,
+  WorkspacePluginsResponse,
+} from "@dispatch/transport-contract";
+
+/**
+ * Plugin HTTP effects — the injected edge that talks to the backend's plugin
+ * manager routes (plan 05) + per-workspace enablement routes (plan 06 §6.6).
+ * Mirrors the workspaces adapter's pattern: `httpBase` + an injected
+ * `fetchImpl` (testable without the network); reads return data or a safe
+ * `null` on failure (non-fatal), mutations return a typed result so a caller
+ * can surface the backend's `{ reason, message }` block.
+ *
+ * Endpoints:
+ * - `GET /plugins` → {@link PluginListResponse} (the two manager tables + missing strip)
+ * - `POST /plugins/scan` → {@link PluginScanResponse} (manual scan; never auto-loads)
+ * - `POST /plugins/:id/load` → {@link PluginOpResponse}
+ * - `POST /plugins/:id/unload` body `{ force }` → {@link PluginOpResponse}
+ * - `POST /plugins/:id/reload` → {@link PluginOpResponse}
+ * - `GET /workspaces/:id/plugins` → {@link WorkspacePluginsResponse} (READ triggers
+ *   read-through materialization)
+ * - `PUT /workspaces/:id/plugins/:pluginId` body `{ state }` →
+ *   {@link SetWorkspacePluginStateResponse} (409 `core-locked` / `unloaded`)
+ * - `GET /workspaces/:id/plugins/providers-status` →
+ *   {@link WorkspacePluginProvidersStatusResponse} (zero-enabled-providers guardrail)
+ */
+
+/** Outcome of a plugin-manager mutation (load / unload / reload). */
+export type PluginOpResult =
+  | { readonly ok: true; readonly response: Extract<PluginOpResponse, { ok: true }> }
+  | {
+      readonly ok: false;
+      readonly error: string;
+      readonly reason?: string;
+      /** For `cascade-needs-force`: the loaded dependents a force would remove. */
+      readonly dependents?: readonly string[];
+    };
+
+/** Outcome of a per-workspace state write (`PUT .../plugins/:pluginId`). */
+export type WorkspaceStateResult =
+  | { readonly ok: true; readonly response: SetWorkspacePluginStateResponse }
+  | { readonly ok: false; readonly error: string; readonly reason?: string };
+
+/** Outcome of the manual scan (`POST /plugins/scan`). */
+export type PluginScanResult =
+  | { readonly ok: true; readonly response: PluginScanResponse }
+  | { readonly ok: false; readonly error: string };
+
+export interface PluginsHttp {
+  list(): Promise<PluginListResponse | null>;
+  scan(): Promise<PluginScanResult>;
+  load(id: string): Promise<PluginOpResult>;
+  unload(id: string, force: boolean): Promise<PluginOpResult>;
+  reload(id: string): Promise<PluginOpResult>;
+  /** Read one workspace's effective plugin states (triggers materialization). */
+  workspacePlugins(workspaceId: string): Promise<WorkspacePluginsResponse | null>;
+  setWorkspaceState(
+    workspaceId: string,
+    pluginId: string,
+    state: "enabled" | "disabled" | "unset",
+  ): Promise<WorkspaceStateResult>;
+  /** The zero-enabled-providers signal for the active workspace (§6.5). */
+  providersStatus(workspaceId: string): Promise<WorkspacePluginProvidersStatusResponse | null>;
+}
+
+async function errorBody(res: Response): Promise<{
+  error?: string;
+  reason?: string;
+  dependents?: readonly string[];
+  message?: string;
+}> {
+  try {
+    return (await res.json()) as {
+      error?: string;
+      reason?: string;
+      dependents?: readonly string[];
+      message?: string;
+    };
+  } catch {
+    return {};
+  }
+}
+
+/**
+ * Map a plugin-manager block/error response to a `PluginOpResult`. The
+ * backend's blocked shape is `{ ok: false, reason, message, dependents? }`;
+ * other failures degrade to `{ error }` only.
+ */
+async function opResult(res: Response): Promise<PluginOpResult> {
+  const body = await errorBody(res);
+  const message = body.message ?? body.error ?? `HTTP ${res.status}`;
+  return {
+    ok: false,
+    error: message,
+    ...(body.reason !== undefined ? { reason: body.reason } : {}),
+    ...(body.dependents !== undefined ? { dependents: body.dependents } : {}),
+  };
+}
+
+export function createPluginsHttp(httpBase: string, fetchImpl: typeof fetch): PluginsHttp {
+  const post = (path: string, body?: unknown): Promise<Response> =>
+    fetchImpl(`${httpBase}${path}`, {
+      method: "POST",
+      ...(body !== undefined
+        ? { headers: { "Content-Type": "application/json" }, body: JSON.stringify(body) }
+        : {}),
+    });
+
+  return {
+    async list(): Promise<PluginListResponse | null> {
+      try {
+        const res = await fetchImpl(`${httpBase}/plugins`);
+        if (!res.ok) return null;
+        return (await res.json()) as PluginListResponse;
+      } catch {
+        return null;
+      }
+    },
+
+    async scan(): Promise<PluginScanResult> {
+      try {
+        const res = await post("/plugins/scan");
+        if (!res.ok)
+          return { ok: false, error: (await errorBody(res)).error ?? `HTTP ${res.status}` };
+        return { ok: true, response: (await res.json()) as PluginScanResponse };
+      } catch (err) {
+        return { ok: false, error: err instanceof Error ? err.message : "Scan request failed" };
+      }
+    },
+
+    async load(id): Promise<PluginOpResult> {
+      try {
+        const res = await post(`/plugins/${encodeURIComponent(id)}/load`);
+        if (!res.ok) return await opResult(res);
+        return {
+          ok: true,
+          response: (await res.json()) as Extract<PluginOpResponse, { ok: true }>,
+        };
+      } catch (err) {
+        return { ok: false, error: err instanceof Error ? err.message : "Load request failed" };
+      }
+    },
+
+    async unload(id, force): Promise<PluginOpResult> {
+      try {
+        const res = await post(`/plugins/${encodeURIComponent(id)}/unload`, { force });
+        if (!res.ok) return await opResult(res);
+        return {
+          ok: true,
+          response: (await res.json()) as Extract<PluginOpResponse, { ok: true }>,
+        };
+      } catch (err) {
+        return { ok: false, error: err instanceof Error ? err.message : "Unload request failed" };
+      }
+    },
+
+    async reload(id): Promise<PluginOpResult> {
+      try {
+        const res = await post(`/plugins/${encodeURIComponent(id)}/reload`);
+        if (!res.ok) return await opResult(res);
+        return {
+          ok: true,
+          response: (await res.json()) as Extract<PluginOpResponse, { ok: true }>,
+        };
+      } catch (err) {
+        return { ok: false, error: err instanceof Error ? err.message : "Reload request failed" };
+      }
+    },
+
+    async workspacePlugins(workspaceId): Promise<WorkspacePluginsResponse | null> {
+      try {
+        const res = await fetchImpl(
+          `${httpBase}/workspaces/${encodeURIComponent(workspaceId)}/plugins`,
+        );
+        if (!res.ok) return null;
+        return (await res.json()) as WorkspacePluginsResponse;
+      } catch {
+        return null;
+      }
+    },
+
+    async setWorkspaceState(workspaceId, pluginId, state): Promise<WorkspaceStateResult> {
+      const body: SetWorkspacePluginStateRequest = { state };
+      try {
+        const res = await fetchImpl(
+          `${httpBase}/workspaces/${encodeURIComponent(workspaceId)}/plugins/${encodeURIComponent(pluginId)}`,
+          {
+            method: "PUT",
+            headers: { "Content-Type": "application/json" },
+            body: JSON.stringify(body),
+          },
+        );
+        if (!res.ok) {
+          const blocked = (await errorBody(res)) as Partial<SetWorkspacePluginStateBlocked> & {
+            error?: string;
+          };
+          return {
+            ok: false,
+            error: blocked.message ?? blocked.error ?? `HTTP ${res.status}`,
+            ...(blocked.reason !== undefined ? { reason: blocked.reason } : {}),
+          };
+        }
+        return { ok: true, response: (await res.json()) as SetWorkspacePluginStateResponse };
+      } catch (err) {
+        return {
+          ok: false,
+          error: err instanceof Error ? err.message : "Set plugin state request failed",
+        };
+      }
+    },
+
+    async providersStatus(workspaceId): Promise<WorkspacePluginProvidersStatusResponse | null> {
+      try {
+        const res = await fetchImpl(
+          `${httpBase}/workspaces/${encodeURIComponent(workspaceId)}/plugins/providers-status`,
+        );
+        if (!res.ok) return null;
+        return (await res.json()) as WorkspacePluginProvidersStatusResponse;
+      } catch {
+        return null;
+      }
+    },
+  };
+}