Add add-on management: registry browser, install, remove (step 5)

Browse the ~270-entry DDEV add-on registry with search, install via
`ddev addon get`, remove via `ddev addon remove` — both routed through
the streaming commandRunner. `addon get`/`remove` support `--project
<name>` directly (unlike snapshot restore), so no cwd trick needed
here. Verified working with the project stopped, per the plan's
requirement.

Found and fixed a real bug via live UI testing: `ddev addon list
--installed --json-output` omits the `raw` key entirely when nothing
is installed (unlike `ddev list`/`ddev snapshot --list`, which include
`raw: null`). The shared runDdevRead helper treated that as an error,
so after removing the last add-on the query errored on refetch and
React Query kept showing the stale cached row instead of clearing it.
Split the helper into runDdevRead (strict, for describeProject where
missing data is a real error) and runDdevReadList (treats missing raw
as empty, for every list-style command) and fixed all four list call
sites to use it.

Verified end-to-end via CDP-driven clicks against the real scratch
project: search filtering, install (streamed output, confirmed via
`ddev addon list --installed` on the CLI), and remove — including
re-confirming after the fix that the installed-add-ons table actually
clears instead of showing stale data.

src/main/ddev.ts

@@ -1,6 +1,12 @@
 import { execFile } from 'child_process'
 import { promisify } from 'util'
-import type { DdevProjectDetail, DdevProjectSummary, DdevSnapshot } from '../shared/types'
+import type {
+  DdevAddonRegistryEntry,
+  DdevInstalledAddon,
+  DdevProjectDetail,
+  DdevProjectSummary,
+  DdevSnapshot
+} from '../shared/types'
 
 const execFileAsync = promisify(execFile)
 
@@ -57,7 +63,8 @@ async function execDdev<T>(args: string[], cwd?: string): Promise<DdevJsonEnvelo
   return envelope
 }
 
-// Read commands (list/describe): the payload lives under `raw`.
+// Read commands where `raw` is always expected on success (describe): throws
+// if it's missing, since that indicates something actually went wrong.
 async function runDdevRead<T>(args: string[], cwd?: string): Promise<T> {
   const envelope = await execDdev<T>(args, cwd)
   if (envelope.raw === undefined) {
@@ -68,6 +75,15 @@ async function runDdevRead<T>(args: string[], cwd?: string): Promise<T> {
   return envelope.raw
 }
 
+// List-style read commands are inconsistent about `raw` when there's nothing
+// to report: `ddev list`/`ddev snapshot --list` include `raw: null`, but
+// `ddev addon list --installed` omits `raw` entirely for "no add-ons found".
+// Treat a missing `raw` as "empty" here rather than an error.
+async function runDdevReadList<T>(args: string[], cwd?: string): Promise<T | undefined> {
+  const envelope = await execDdev<T>(args, cwd)
+  return envelope.raw
+}
+
 // ddev sometimes prints non-JSON progress lines before the final JSON envelope
 // (opt-in prompts, deprecation notices); the envelope is always the last line.
 function tryParseLastJsonLine<T>(output: string): T | null {
@@ -85,7 +101,7 @@ function tryParseLastJsonLine<T>(output: string): T | null {
 }
 
 export async function listProjects(): Promise<DdevProjectSummary[]> {
-  const raw = await runDdevRead<DdevProjectSummary[] | null>(['list'])
+  const raw = await runDdevReadList<DdevProjectSummary[] | null>(['list'])
   return raw ?? []
 }
 
@@ -97,9 +113,25 @@ export async function describeProject(name: string): Promise<DdevProjectDetail>
 // resolve the project, so every snapshot command runs with cwd = approot
 // rather than passing the project name positionally like other commands.
 export async function listSnapshots(name: string, approot: string): Promise<DdevSnapshot[]> {
-  const raw = await runDdevRead<Record<string, DdevSnapshot[] | null>>(
+  const raw = await runDdevReadList<Record<string, DdevSnapshot[] | null>>(
     ['snapshot', '--list'],
     approot
   )
-  return raw[name] ?? []
+  return raw?.[name] ?? []
+}
+
+export async function listAddonRegistry(): Promise<DdevAddonRegistryEntry[]> {
+  const raw = await runDdevReadList<DdevAddonRegistryEntry[] | null>(['addon', 'list'])
+  return raw ?? []
+}
+
+export async function listInstalledAddons(name: string): Promise<DdevInstalledAddon[]> {
+  const raw = await runDdevReadList<DdevInstalledAddon[] | null>([
+    'addon',
+    'list',
+    '--installed',
+    '--project',
+    name
+  ])
+  return raw ?? []
 }

src/main/index.ts

@@ -5,6 +5,7 @@ import icon from '../../resources/icon.png?asset'
 import { registerProjectsIpc } from './ipc/projects'
 import { registerTerminalIpc } from './ipc/terminal'
 import { registerDatabaseIpc } from './ipc/database'
+import { registerAddonsIpc } from './ipc/addons'
 
 function createWindow(): void {
   // Create the browser window.
@@ -56,6 +57,7 @@ app.whenReady().then(() => {
   registerProjectsIpc()
   registerTerminalIpc()
   registerDatabaseIpc()
+  registerAddonsIpc()
 
   createWindow()
 

src/main/ipc/addons.ts

@@ -0,0 +1,16 @@
+import { ipcMain } from 'electron'
+import { listAddonRegistry, listInstalledAddons } from '../ddev'
+import { runStreamed } from '../commandRunner'
+
+export function registerAddonsIpc(): void {
+  ipcMain.handle('addons:listRegistry', () => listAddonRegistry())
+  ipcMain.handle('addons:listInstalled', (_event, name: string) => listInstalledAddons(name))
+
+  ipcMain.handle('addons:install', (event, operationId: string, name: string, addonRepo: string) =>
+    runStreamed(operationId, ['addon', 'get', addonRepo, '--project', name], event.sender)
+  )
+
+  ipcMain.handle('addons:remove', (event, operationId: string, name: string, addonName: string) =>
+    runStreamed(operationId, ['addon', 'remove', addonName, '--project', name], event.sender)
+  )
+}