fix(aggregator): preserve distinct provider display names

pm-stack/aggregator/src/provider-display.ts

@@ -2,7 +2,8 @@
 //
 // Rule 0 (#1823, Drew 2026-11-07): a leading underscore is a
 // config/source-level ownership marker (fleet-built providers carry
-// it: _claude, _antigravity, ...). Display surfaces strip it — the
+// it: _claude, _antigravity, ...). Display surfaces strip it unless
+// that would collide with another provider in the rendered set — the
 // canonical id keeps it everywhere else.
 //
 // Rule (dashboard only, markup only): a provider whose name ends in
@@ -35,13 +36,16 @@ function providerHead(name: string): string {
  * same set.
  */
 export function providerDisplayNames(names: Iterable<string>): Map<string, string> {
-  const list = [...names].map((name) => {
+  const originals = [...names];
+  const originalSet = new Set(originals);
+  const list = originals.map((name) => {
     const head = providerHead(name);
-    return head.startsWith("_") ? head.slice(1) + name.slice(head.length) : name;
+    if (!head.startsWith("_")) return name;
+    const stripped = head.slice(1) + name.slice(head.length);
+    return originalSet.has(stripped) ? name : stripped;
   });
   const heads = new Set(list.map(providerHead));
   const out = new Map<string, string>();
-  const originals = [...names];
   for (let i = 0; i < list.length; i++) {
     const name = list[i];
     const original = originals[i];

pm-stack/aggregator/test/provider-display.test.ts

@@ -35,6 +35,35 @@ describe("providerDisplayNames (#6125)", () => {
     expect([...names.keys()].sort()).toEqual(["_antigravity.claude-gpt", "_antigravity.gemini", "_claude", "meta"]);
   });
 
+  test("reads one-shot iterables exactly once and preserves their input keys", () => {
+    const inputs = ["_claude", "meta", "_antigravity.gemini"];
+    function* providers() {
+      yield* inputs;
+    }
+
+    const expected: [string, string][] = [
+      ["_claude", "claude"],
+      ["meta", "meta"],
+      ["_antigravity.gemini", "antigravity.gemini"],
+    ];
+    expect([...providerDisplayNames(providers())]).toEqual(expected);
+
+    const keys = new Map(inputs.map((name) => [name, true] as const)).keys();
+    expect([...providerDisplayNames(keys)]).toEqual(expected);
+  });
+
+  test("keeps the ownership marker when stripping it would collide with a plain provider", () => {
+    const names = providerDisplayNames(["_claude", "claude"]);
+    expect(names.get("_claude")).toBe("_claude");
+    expect(names.get("claude")).toBe("claude");
+  });
+
+  test("keeps dotted renamed providers distinguishable from their plain sibling", () => {
+    const names = providerDisplayNames(["_antigravity.gemini", "antigravity.gemini"]);
+    expect(names.get("_antigravity.gemini")).toBe("_antigravity.gemini");
+    expect(names.get("antigravity.gemini")).toBe("antigravity.gemini");
+  });
+
   test("non-direct names are untouched", () => {
     const names = providerDisplayNames(["mistral", "openai.main", "cline-pass", "direct"]);
     expect(names.get("mistral")).toBe("mistral");