fix(cli): register web prompt context before boot

apps/cli/src/app-cli-entry.ts

@@ -155,6 +155,8 @@ export interface AppCLIEntryOptions {
   workspaceRoot?: string
   /** Extra authorities for the /api browser-trust fence (`host` or `host:port`), appended to the derived LAN IP literals. */
   trustedHosts?: string[]
+  /** Surface setup registered after Loader installation and before any config-tree entry mounts. */
+  prepare?: (ctx: Context) => Promise<void> | void
 }
 
 /**
@@ -180,8 +182,8 @@ export class AppCLIEntry {
   constructor(private readonly options: AppCLIEntryOptions) {}
 
   /**
-   * Run the boot chain: patch composition → Loader include boot (dev row
-   * before await) → fail-loud triple.
+   * Run the boot chain: patch composition → Loader installation → surface
+   * preparation → config-tree boot (dev row before await) → fail-loud triple.
    * @returns the settled root context and the listening port.
    */
   async run(): Promise<{ ctx: Context; port: number }> {
@@ -246,7 +248,7 @@ export class AppCLIEntry {
     if (telemetryPatch !== undefined) this.patches.push(telemetryPatch)
   }
 
-  /** Shared Loader boot; the dev HMR row mounts before await so the activation audit covers it. */
+  /** Shared Loader boot; surface preparation precedes the tree, and the dev HMR row precedes the activation audit. */
   private async bootTree(): Promise<void> {
     // One include of the shared base with every overlay as a sibling patch
     // list: patches never cross an include boundary, so nesting them would
@@ -260,6 +262,7 @@ export class AppCLIEntry {
       ...this.patches,
     ]
     this.ctx = await boot('dsh', resolve(this.options.configPath), patches, async (ctx) => {
+      await this.options.prepare?.(ctx)
       if (this.options.dev) await ctx.loader.create({ name: '@deepseek-ai/dsh-client-hmr' })
     })
   }

apps/cli/src/web.ts

@@ -23,17 +23,18 @@ const WEB_SURFACE_PROMPT = 'You are interacting with the user through the DeepSe
   + 'The browser provides no implicit DOM, route, or screenshot context.'
 
 /**
- * Add the launcher-owned source location and Web-surface orientation after the
- * shared config tree settles. The request header logs both sections with every
- * model-visible prompt.
- * @param ctx - settled Web application context.
+ * Register the launcher-owned source location and Web-surface orientation
+ * before the shared config tree mounts. The injection installs both sections
+ * when `systemPrompt` activates; because it precedes the Loader entries, later
+ * prompt consumers observe them on their first activation.
+ * @param ctx - Web root context with Loader installed but no config tree mounted.
  * @param sourceRoot - absolute checkout root resolved from the launcher module.
  */
-export function installWebPromptContext(ctx: Context, sourceRoot: string): void {
-  const systemPrompt = ctx.get('systemPrompt')
-  if (systemPrompt === undefined) throw new Error('dsh web: systemPrompt service missing after settled boot')
-  addHarnessSourceSection(ctx, sourceRoot)
-  systemPrompt.section({ name: 'app:web-surface', order: -98, text: WEB_SURFACE_PROMPT })
+export function prepareWebPromptContext(ctx: Context, sourceRoot: string): void {
+  ctx.inject(['systemPrompt'], (promptCtx) => {
+    addHarnessSourceSection(promptCtx, sourceRoot)
+    promptCtx.systemPrompt.section({ name: 'app:web-surface', order: -98, text: WEB_SURFACE_PROMPT })
+  })
 }
 
 // Display-only mirror of the webserver schema's loopback host: the address the
@@ -65,13 +66,13 @@ export async function runWeb(
     overlayPath: WEB_OVERLAY,
     ...config !== undefined && { extraOverlayPath: resolveConfigPath(config, undefined) },
     dev,
+    prepare: (ctx) => { prepareWebPromptContext(ctx, SOURCE_ROOT) },
     ...host !== undefined && { host },
     ...port !== undefined && { port },
     ...workspaceRoot !== undefined && { workspaceRoot },
     ...trustedHosts !== undefined && { trustedHosts },
   })
   const { ctx, port: boundPort } = await entry.run()
-  installWebPromptContext(ctx, SOURCE_ROOT)
 
   let exiting = false
   const shutdown = (code: number): void => {

apps/cli/tests/web-prompt-context.spec.ts

@@ -0,0 +1,29 @@
+import { sep } from 'node:path'
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import { HARNESS_SOURCE_SECTION } from '@deepseek-ai/dsh-app-boot'
+import { prepareWebPromptContext } from '../src/web.ts'
+
+describe('prepareWebPromptContext', () => {
+  it('installs both sections before a later systemPrompt consumer activates', async () => {
+    const ctx = new Context()
+    const sourceRoot = `${sep}opt${sep}harness-src`
+    let observedNames: string[] | undefined
+    try {
+      prepareWebPromptContext(ctx, sourceRoot)
+      const consumer = ctx.inject(['systemPrompt'], async (promptCtx) => {
+        const assembly = await promptCtx.systemPrompt.assemble()
+        observedNames = assembly.sections.map(section => section.name)
+      })
+
+      await ctx.plugin(SystemPrompt, { persona: 'You are a coding agent.' })
+      await consumer
+
+      expect(observedNames).toContain(HARNESS_SOURCE_SECTION)
+      expect(observedNames).toContain('app:web-surface')
+    } finally {
+      await ctx.fiber.dispose()
+    }
+  })
+})