docs: remove competitor references; retire the mention assertion (#929)

Per Brian's direction: reword every prose reference to the upstream
package's chat-frontend mount generically — blog post, runtimes docs,
cockpit guide, service README and comment, and two internal planning
docs. Lockfile occurrences are upstream's machine-generated dependency
tree and stay.

The never-executed competitor assertion in mit-cutover.spec.mjs is
deleted — no allowlist or CI enforcement wanted for this; it is an
editorial rule applied at writing time. With that block gone and the
stray licensing artifact removed (#917), the spec's remaining MIT
assertions pass, so it re-enters the scripts test suite and runs in CI
for the first time.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: blove

apps/website/content/blog/2026-08-31-we-measured-the-runtime-swap.mdx

@@ -29,7 +29,7 @@ The short version is that the contract held where it mattered and broke in two p
 Each runtime got a server standing on its upstream AG-UI integration, not on anything we wrote to make the numbers look good.
 Microsoft Agent Framework runs behind `agent-framework-ag-ui`.
 Strands runs behind the community `ag-ui-strands` bridge, pinned to a git reference because the published release crashes on multi-agent routes.
-Mastra needed about two hundred lines of Node hosting code, because the upstream package ships an in-process bridge and a CopilotKit mount rather than a plain HTTP endpoint.
+Mastra needed about two hundred lines of Node hosting code, because the upstream package ships an in-process bridge and a mount for its own chat frontend, rather than a plain HTTP endpoint.
 
 Every server was driven with live model calls until it produced each surface we cared about: streaming text, a tool call, shared state, and a human approval.
 The raw event stream from each of those runs was saved.

apps/website/content/docs/runtimes/mastra/how-it-connects.mdx

@@ -9,7 +9,7 @@ This page records the AG-UI wire behavior measured for Mastra on 2026-08-31. It
 
 ## Transport is Threadplane's, not upstream's
 
-`@ag-ui/mastra` ships an in-process `MastraAgent` bridge and a CopilotKit runtime mount, and no plain AG-UI HTTP endpoint. The service in [`deployments/ag-ui-mastra`](https://github.com/cacheplane/angular-agent-framework/tree/main/deployments/ag-ui-mastra) supplies the missing endpoint.
+`@ag-ui/mastra` ships an in-process `MastraAgent` bridge and a mount for its own chat frontend runtime, and no plain AG-UI HTTP endpoint. The service in [`deployments/ag-ui-mastra`](https://github.com/cacheplane/angular-agent-framework/tree/main/deployments/ag-ui-mastra) supplies the missing endpoint.
 
 | Route | Method | Auth | Notes |
 |---|---|---|---|

apps/website/content/docs/runtimes/mastra/overview.mdx

@@ -25,7 +25,7 @@ The hosted example runs at [examples.threadplane.ai/runtimes/mastra](https://exa
 
 ## Upstream ships no HTTP endpoint
 
-`@ag-ui/mastra` provides an in-process `MastraAgent` bridge and a CopilotKit runtime mount. It does not provide a plain AG-UI HTTP endpoint, which is what `@threadplane/ag-ui` connects to.
+`@ag-ui/mastra` provides an in-process `MastraAgent` bridge and a mount for its own chat frontend runtime. It does not provide a plain AG-UI HTTP endpoint, which is what `@threadplane/ag-ui` connects to.
 
 Threadplane therefore maintains a small hosting service, [`deployments/ag-ui-mastra`](https://github.com/cacheplane/angular-agent-framework/tree/main/deployments/ag-ui-mastra). It accepts `POST /agent/<topic>`, calls `MastraAgent.run(input)`, and writes one Server-Sent Events frame per AG-UI event. It is deliberately hand-written rather than generated: the Python generator targets one aggregated FastAPI process, and Mastra is a different language on a different hosting lane.
 

cockpit/runtimes/mastra/angular/docs/guide.md

@@ -29,8 +29,9 @@ store would orphan every pending approval across HTTP requests.
 ## The hosting service (Node lane)
 
 Upstream `@ag-ui/mastra` ships no plain AG-UI HTTP endpoint — only the
-in-process `MastraAgent` bridge and a CopilotKit runtime mount. The backend
-is therefore the hand-written Node service `deployments/ag-ui-mastra/`:
+in-process `MastraAgent` bridge and a mount for its own chat frontend
+runtime. The backend is therefore the hand-written Node service
+`deployments/ag-ui-mastra/`:
 `server.mjs` subscribes to `MastraAgent.run(input)` (the raw AG-UI event
 Observable) and encodes each event as one SSE `data:` frame — exactly what
 `@ag-ui/client`'s `HttpAgent` consumes. It mirrors the Python lane's

deployments/ag-ui-mastra/README.md

@@ -4,10 +4,11 @@ Hand-written Node hosting service for the **Mastra** AG-UI runtime — Lane B of
 the runtime-portability matrix (`docs/superpowers/plans/2026-08-31-runtime-portability-matrix.md`).
 
 Upstream `@ag-ui/mastra` ships **no** plain AG-UI HTTP endpoint (only the
-in-process `MastraAgent` bridge and a CopilotKit runtime mount). This service
-is that missing endpoint: `POST /agent/<topic>` → `MastraAgent.run(input)` →
-one SSE `data:` frame per AG-UI event. It is deliberately hand-written, not
-generated: the Python generator (`scripts/generate-ag-ui-deployment-config.ts`)
+in-process `MastraAgent` bridge and a mount for its own chat frontend
+runtime). This service is that missing endpoint: `POST /agent/<topic>` →
+`MastraAgent.run(input)` → one SSE `data:` frame per AG-UI event. It is
+deliberately hand-written, not generated: the Python generator
+(`scripts/generate-ag-ui-deployment-config.ts`)
 targets one aggregated FastAPI process, and Mastra is a different language and
 hosting lane.
 

deployments/ag-ui-mastra/server.mjs

@@ -2,8 +2,8 @@
 // AG-UI HTTP/SSE hosting service for Mastra agents (Lane B).
 //
 // Upstream @ag-ui/mastra ships NO plain AG-UI HTTP endpoint — only the
-// in-process `MastraAgent` bridge and a CopilotKit runtime mount. This
-// hand-written service is the missing piece: it subscribes to
+// in-process `MastraAgent` bridge and a mount for its own chat frontend
+// runtime. This hand-written service is the missing piece: it subscribes to
 // `MastraAgent.run(input)` (the raw AG-UI event Observable) and encodes each
 // event as an SSE `data: {json}` frame — exactly what @ag-ui/client's
 // HttpAgent consumes, and exactly what the Python lane's FastAPI bridges

docs/superpowers/plans/2026-08-31-runtime-portability-matrix.md

@@ -136,7 +136,7 @@ our own demo-backend convention; no third party emits it.
 | runtime | cost | notes |
 |---|---|---|
 | Microsoft | ~30 min | `agent-framework-ag-ui` is the real bridge, not the upstream dojo shim. **Azure creds NOT required** — plain `OPENAI_API_KEY`. Deps co-resolve with the existing lane. |
-| Mastra | ~15 min | Upstream ships **no** plain AG-UI HTTP endpoint — only in-process `MastraAgent` + a CopilotKit runtime mount. A ~200-line Node shim was wire-correct first try. |
+| Mastra | ~15 min | Upstream ships **no** plain AG-UI HTTP endpoint — only an in-process `MastraAgent` and a mount for its own chat frontend runtime. A ~200-line Node shim was wire-correct first try. |
 | Strands | ~5 min | ⚠️ **PyPI `ag-ui-strands` 0.3.0 is stale and crashes on multi-agent routes** — install from a git ref, not the release. |
 
 ## Phase 2 sequencing (approved 2026-08-31)

docs/superpowers/specs/2026-08-27-basecamp-homepage-design.md

@@ -162,8 +162,8 @@ committed. Three corrections to the design content:
   ("most packages MIT, chat commercially licensed") — it is now an unqualified
   yes: *"Can I use every package commercially without a license fee?" → Yes,
   MIT.* The old licensing FAQ item is gone from main; do not resurrect it.
-- **The CopilotKit migration question no longer exists.** #881 scrubbed
-  CopilotKit from the entire site (FAQ item, logo, differentiator copy). The
+- **The competitor-migration question no longer exists.** #881 scrubbed the
+  competitor's name from the entire site (FAQ item, logo, differentiator copy). The
   surviving-FAQ list above reflects that; reintroducing the comparison would
   run against a deliberate decision on main.
 - **The telemetry Yes-wall row strengthens.** Main's language is now "package