feat(showcase): per-framework D4/D6 aimock fixtures + D6 probe driver + harness scoping (CopilotKit#5022)

## Summary

Lands the per-framework fixture reorg + D6 probe driver + harness
scoping work that was parked behind the ag-ui header-forwarding chain
(now shipped via CopilotKit#4984, CopilotKit#4951, CopilotKit#5015, CopilotKit#5016).

This is the foundational data layer the D6 dashboard needs to populate.
Slice 1 (CopilotKit#5018) shipped the rendering plumbing earlier today; this PR
makes d6:<slug>/<featureId> PB rows start flowing.

## What ships

- 477 per-integration aimock fixtures organized under `d4/`, `d6/`,
`shared/` directories (flat `d5-all.json` / `feature-parity.json`
deprecated)
- Every fixture keyed by `match.context` to enforce per-integration
isolation (server-side routing already merged in aimock CopilotKit#226)
- D6 all-pills probe driver + per-integration scoping in
showcase-harness
- X-AIMock-Context header propagation in 18 integration Playwright
configs
- D6-ceiling chip color algorithm (D6 is integration-scoped aggregate,
maxPossible raised from 5 to 6)
- Docker-compose updates for the new fixture dir layout
- 12 HITL fixtures migrated from main's d5-all.json additions into
shared/_migrated-from-d5-all-hitl.json

## Why this is safe to ship now

- ag-ui/LangGraph configurable+context HTTP 400 blocker is fixed (CopilotKit#5015
+ CopilotKit#5016)
- sdk-python 0.1.91 with `_extract_forwarded_headers_from_config` is on
PyPI and pinned across showcase
- aimock server-side context routing is already live (aimock CopilotKit#226)
- The SDK overlay hacks the branch carried locally are now redundant —
discarded before rebase

## Pre-existing CI note

`@copilotkit/web-inspector:test` has a pre-existing failure
(`window.localStorage.clear is not a function` in telemetry tests) —
verified on clean main checkout. Not introduced by this PR.

## Follow-ups

- Distribute migrated HITL fixtures from shared/_migrated-from-*.json
into per-integration d6/<slug>/ files
- Slice 2: D6 drilldown DIMENSIONS + AdaptiveStatsBar rollup section
- LGP gen-ui-interrupt second-pill framework bug (Hypothesis B in
useInterrupt hook)

Author: jpr5

.claude-plugin/marketplace.json

@@ -13,7 +13,7 @@
       "name": "copilotkit",
       "source": "./",
       "description": "AI agent skills for CopilotKit — setup, develop, integrate, debug, upgrade, and contribute to CopilotKit projects",
-      "version": "1.57.4",
+      "version": "1.58.0",
       "author": {
         "name": "CopilotKit",
         "url": "https://copilotkit.ai"

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "copilotkit",
   "description": "AI agent skills for CopilotKit — setup, develop, integrate, debug, upgrade, and contribute to CopilotKit projects",
-  "version": "1.57.4",
+  "version": "1.58.0",
   "author": {
     "name": "CopilotKit",
     "url": "https://copilotkit.ai"

.github/workflows/plugin-skills-check.yml

@@ -33,6 +33,7 @@ concurrency:
 jobs:
   check:
     runs-on: ubuntu-latest
+    timeout-minutes: 10
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
         with:

.oxfmtrc.json

@@ -9,6 +9,9 @@
     ".github/actions/changesets-action/src/run.ts",
     "examples/v1/_legacy/copilot-anthropic-pinecone/src/app/api/copilotkit/route.ts",
     "examples/v1/_legacy/copilot-openai-mongodb-atlas-vector-search/src/app/api/copilotkit/route.ts",
-    "packages/web-inspector/src/styles/generated.css"
+    "packages/web-inspector/src/styles/generated.css",
+    "showcase/aimock/shared/**",
+    "showcase/aimock/d4/**",
+    "showcase/aimock/d6/**"
   ]
 }

lefthook.yml

@@ -37,6 +37,9 @@ pre-commit:
       # the commit.
       exclude:
         - "docs/**"
+        - "showcase/aimock/shared/**"
+        - "showcase/aimock/d4/**"
+        - "showcase/aimock/d6/**"
       # Use `set --` so the staged files become positional args; this is the
       # only shell-portable way to test "are there any" without breaking on
       # multi-file expansion. The old `[ -n "{staged_files}" ]` form failed

showcase/GOTCHAS.md

@@ -120,6 +120,18 @@ What we learned from getting all 18 integrations to D5 green. Many of these are
 
 ---
 
+## Fixture Authoring Gotchas
+
+**`context` field is required for D4/D6 fixtures.** Context routing (aimock `--context-field`) uses `match.context` to isolate fixtures per integration. Omitting `context` means the fixture matches globally -- every integration hits it, and the first match wins regardless of which integration made the request. Always set `match.context` for any fixture loaded through per-integration routing.
+
+**`match.context` must equal the integration slug.** The slug is the directory name under `showcase/integrations/` (e.g., `langgraph-python`, `mastra`, `spring-ai`). A mismatch between the context value and the slug silently drops the fixture from that integration's match pool -- aimock falls through to the next fixture or returns an unmatched response.
+
+**Never combine `content` and `toolCalls` in a single fixture.** A fixture must return either text (`content`) or tool calls (`toolCalls`), not both. Combining them produces undefined behavior: some providers stream the text, others stream the tool call, and the order is non-deterministic. Split into two fixtures with `sequenceIndex` if you need text followed by a tool call (or vice versa).
+
+**`hasToolResult: false` breaks multi-pill flows.** When a fixture returns `toolCalls` with `hasToolResult: false`, aimock treats the conversation as complete after the tool call -- it will not match a follow-up turn where the client sends back the tool result. In multi-pill flows (D6), the agent cycles through multiple tool calls and text responses. Use `hasToolResult: true` (or omit it, since `true` is the default) so aimock expects the client to send tool results and continues matching subsequent turns.
+
+---
+
 ## What Was "Green" But Still Wrong
 
 1. **18 copies of identical frontend code** — every fix was a blitz. One missed integration = one regression.

showcase/QA-COVERAGE.md

@@ -79,6 +79,13 @@ This matrix tracks what testing exists for each demo and the Sales Dashboard sta
 - `showcase_deploy.yml` -- deployment pipeline
 - **Gap:** No automatic Playwright E2E in CI on every PR; aimock E2E requires manual trigger
 
+## Probe Depth Coverage
+
+| Depth | Probe Name       | Cadence    | What "Green" Means                                |
+| ----- | ---------------- | ---------- | ------------------------------------------------- |
+| D5    | e2e-demos        | hourly :10 | All per-integration smoke probes pass             |
+| D6    | d6-all-pills-e2e | hourly :40 | All demo cells pass across every integration pill |
+
 ## Recommended Next Steps
 
 1. **Add aimock fixtures** for gen-ui-tool-based (haiku), gen-ui-agent (task steps), shared-state (recipe/deals/document), subagents (travel), and HITL (interrupt with steps)

showcase/aimock/Dockerfile

@@ -1,4 +1,6 @@
 FROM ghcr.io/copilotkit/aimock:latest
-COPY d5-all.json /fixtures/d5-all.json
-COPY smoke.json /fixtures/smoke.json
-COPY feature-parity.json /fixtures/feature-parity.json
+
+# Depth-organized fixture directories
+COPY shared/ /fixtures/shared/
+COPY d4/ /fixtures/d4/
+COPY d6/ /fixtures/d6/

showcase/aimock/README.md

@@ -10,6 +10,24 @@ aimock ([`@copilotkit/aimock`](https://www.npmjs.com/package/@copilotkit/aimock)
 
 The showcase deployment runs aimock in proxy mode — `--proxy-only` with real upstream URLs configured for each provider. Unmatched requests are forwarded to the real API; matched requests short-circuit with the fixture response. This makes the sidecar safe to deploy as a general-purpose smoke-test aid: tests that hit fixture-matched prompts get deterministic responses, and anything else just falls through.
 
+## Directory Structure
+
+```
+showcase/aimock/
+  shared/              Fixtures loaded by ALL integrations (smoke, universal prompts)
+  d4/                  D4-depth fixtures — per-integration, single-demo coverage
+    <slug>/            One directory per integration slug (e.g. langgraph-python/)
+  d6/                  D6-depth fixtures — per-integration, all-pills coverage
+    <slug>/            One directory per integration slug
+  feature-parity.json  Legacy flat fixture file (pre-context-routing)
+  smoke.json           Minimal smoke fixture
+  README.md            This file
+```
+
+**Context routing.** D4 and D6 fixtures use aimock's `--context-field` flag to scope fixture matching by integration. Each integration's dev server passes its slug as the `context` value in LLM requests (via `X-AIMock-Context` header or request body field). Aimock only considers fixtures whose `match.context` equals the incoming context value, so `d4/langgraph-python/` fixtures never interfere with `d4/mastra/` fixtures even if they share the same `userMessage` pattern.
+
+**Per-integration isolation.** Every `<slug>/` directory contains fixtures specific to that integration. This prevents cross-contamination: if `mastra` needs a different tool name than `langgraph-python` for the same demo, each has its own fixture file. The `shared/` directory holds fixtures that apply regardless of context (e.g., smoke checks, universal greeting prompts).
+
 ## Fixtures in this directory
 
 - **`feature-parity.json`** — 35+ fixtures covering the nine showcase demos across 17 packages: agentic chat (weather, backgrounds, themes), tool rendering (pie/bar charts, weather cards), HITL (plans, steps, approvals), Sales Dashboard (deals, pipelines, todos), and assorted meeting/flight/greeting prompts. Consumed by the per-package `test_e2e-showcase-on-demand` Playwright suites and loaded at Railway boot via GitHub raw URL.