fix(prompt): resolve repeated root mentions without sentinels (#864)

I removed the temporary root markers from prompt preparation. Each `@./`
or `@.` reference now resolves directly, so repeated references no
longer send `___ROOT___` to the model.

I added regression tests for repeated references, literal marker text,
pasted content and display metadata, shell input and command arguments.
All three new tests fail before the fix; all 21 targeted tests and UI
typechecking pass afterward.

I also built the Tauri resources and passed the packaged-resource
checks. I did not replace the installed app or restart the shared
daemon.

Fixes #863

packages/ui/src/components/prompt-input/submitPrompt.test.ts

@@ -15,6 +15,19 @@ describe("resolvePromptDelivery", () => {
 })
 
 describe("preparePromptSubmission", () => {
+  it("resolves repeated root mentions in history, shell input and command arguments", () => {
+    const text = "@./a @./b @. @."
+    const expected = "./a ./b ./ ./"
+
+    const message = preparePromptSubmission({ mode: "message", text, attachments: [] })
+    assert.equal(message.historyEntry, expected)
+    assert.equal(message.submitPrompt, text)
+    assert.equal(preparePromptSubmission({ mode: "shell", text, attachments: [] }).submitPrompt, expected)
+    const command = preparePromptSubmission({ mode: "slash", text, attachments: [], commandToken: "/review", commandArgs: text })
+    assert.equal(command.resolvedCommandArgs, expected)
+    assert.equal(command.submitPrompt, `/review ${expected}`)
+  })
+
   it("keeps placeholder-backed pasted text intact for message submission while resolving history text", () => {
     const attachment = createTextAttachment("alpha\nbeta\ngamma\ndelta", "pasted #1 (4 lines)", "paste-1.txt")
 

packages/ui/src/lib/prompt-display-metadata.test.ts

@@ -1,10 +1,34 @@
 import assert from "node:assert/strict"
 import { describe, it } from "node:test"
 
-import { createTextAttachment } from "../types/attachment"
+import { createFileAttachment, createTextAttachment } from "../types/attachment"
 import { preparePromptDisplayText, resolvePastedPlaceholders, splitPromptDisplaySections } from "./prompt-display-metadata"
 
 describe("preparePromptDisplayText", () => {
+  it("resolves every root mention without changing parent paths or literal marker text", () => {
+    const prompt = "@./a @./b @. @. @.. @../c ___ROOT___ ___ROOT_NOSLASH___"
+    const expected = "./a ./b ./ ./ @.. @../c ___ROOT___ ___ROOT_NOSLASH___"
+    const attachments = [createFileAttachment("./a", "a"), createTextAttachment(".", "path:.", ".")]
+
+    assert.equal(resolvePastedPlaceholders(prompt, attachments), expected)
+    assert.equal(preparePromptDisplayText(prompt, attachments).promptToSend, expected)
+  })
+
+  it("preserves pasted text and display sections alongside repeated root mentions", () => {
+    const pasted = "@./verbatim ___ROOT___ ___ROOT_NOSLASH___"
+    const attachment = createTextAttachment(pasted, "pasted #1", "paste-1.txt")
+    const prompt = "@./a @./b\n[pasted #1]\n@. @."
+    const prepared = preparePromptDisplayText(prompt, [attachment])
+
+    assert.equal(prepared.promptToSend, `./a ./b\n${pasted}\n./ ./`)
+    assert.equal(resolvePastedPlaceholders(prompt, [attachment]), prepared.promptToSend)
+    assert.deepEqual(splitPromptDisplaySections(prepared.promptToSend, prepared.displayMetadata), [
+      { kind: "inline", text: "./a ./b\n" },
+      { kind: "pasted", text: pasted },
+      { kind: "inline", text: "\n./ ./" },
+    ])
+  })
+
   it("keeps pasted text fully visible to the model while storing display metadata", () => {
     const attachment = createTextAttachment("line 1\nline 2\nline 3\nline 4", "pasted #1 (4 lines)", "paste-1.txt")
 

packages/ui/src/lib/prompt-display-metadata.ts

@@ -67,8 +67,8 @@ function resolvePathMentions(prompt: string, attachments: Attachment[] = []): st
 
   let result = prompt
 
-  result = result.replace(/@(\.\/)/g, "___ROOT___")
-  result = result.replace(/@(\.)(?!\.)/g, "___ROOT_NOSLASH___")
+  result = result.replace(/@(\.\/)/g, "./")
+  result = result.replace(/@(\.)(?!\.)/g, "./")
 
   const allPaths = new Set<string>()
   for (const path of fileAttachments) {
@@ -85,9 +85,6 @@ function resolvePathMentions(prompt: string, attachments: Attachment[] = []): st
     result = result.replace(`@${withoutPrefix}/`, `${withPrefix}/`)
   }
 
-  result = result.replace("___ROOT___", "./")
-  result = result.replace("___ROOT_NOSLASH___", "./")
-
   return result
 }