docs(#794): align AGENTS.md and ARCHITECTURE.md with @<group> MCP routing

The PR #984 reviewer flagged that both top-level docs still listed the
removed `group_query`, `group_contracts`, and `group_status` MCP tools.
Bring them in line with the actual MCP surface introduced by #794:

- `AGENTS.md` Tools Quick Reference now lists `query`/`context`/`impact`
  in group mode (`repo: "@<groupName>"`) and drops the three removed
  group_* tools. Adds the two new resources
  (`gitnexus://group/{name}/contracts` + `/status`) to the Resources
  table and a 1.5.0 changelog entry.
- `ARCHITECTURE.md` MCP tools table is trimmed to `group_list` and
  `group_sync`, with a paragraph + resource table describing the
  group-aware behaviour of `query`/`context`/`impact` and the bridge
  fan-out for cross-repo impact. "Where to change what" now points at
  `src/core/group/` for cross-repo work.

Made-with: Cursor

AGENTS.md

@@ -47,6 +47,7 @@ Commands and gotchas live under **Repo reference** below and in **[CONTRIBUTING.
 
 | Date | Version | Change |
 |------|---------|--------|
+| 2026-04-19 | 1.5.0 | Cross-repo impact (#794): `impact`/`query`/`context` accept `repo: "@<group>"` + `service`. Removed `group_query`/`group_contracts`/`group_status` MCP tools; added `gitnexus://group/{name}/contracts` and `gitnexus://group/{name}/status` resources. |
 | 2026-04-16 | 1.4.0 | Fixed: web UI description, pre-commit behavior, MCP tools (7->16), added gitnexus-shared, removed stale vite-plugin-wasm gotcha. |
 | 2026-04-13 | 1.3.0 | Updated GitNexus index stats after DAG refactor. |
 | 2026-03-24 | 1.2.0 | Fixed gitnexus:start block duplication. |
@@ -107,10 +108,12 @@ Indexed as **GitNexus** (4325 symbols, 10556 relationships, 300 execution flows)
 | `tool_map` | MCP/RPC tool definitions | `gitnexus_tool_map({})` |
 | `shape_check` | Response shape vs consumer access | `gitnexus_shape_check({route: "/api/users"})` |
 | `group_list` | List repo groups | `gitnexus_group_list({})` |
-| `group_query` | Cross-repo search in a group | `gitnexus_group_query({name: "myGroup", query: "auth"})` |
 | `group_sync` | Rebuild group Contract Registry | `gitnexus_group_sync({name: "myGroup"})` |
-| `group_contracts` | Inspect group contracts | `gitnexus_group_contracts({name: "myGroup"})` |
-| `group_status` | Group staleness report | `gitnexus_group_status({name: "myGroup"})` |
+| `query` (group mode) | Cross-repo search in a group (RRF-merged) | `gitnexus_query({repo: "@myGroup", query: "auth"})` |
+| `context` (group mode) | 360° view across all member repos | `gitnexus_context({repo: "@myGroup", name: "validateUser"})` |
+| `impact` (group mode) | Cross-repo blast radius via Contract Bridge | `gitnexus_impact({repo: "@myGroup", target: "X", direction: "upstream"})` |
+
+> Group mode: pass `repo: "@<groupName>"` to fan out across all member repos, or `repo: "@<groupName>/<memberPath>"` to target a single member (path keys from `group.yaml`). Optional `service: "<monorepo/path>"` filters by service root. Group-level state (contracts, staleness) lives in the resources table below — there are **no** `group_query` / `group_context` / `group_impact` / `group_contracts` / `group_status` MCP tools.
 
 ## Impact Risk Levels
 
@@ -128,6 +131,8 @@ Indexed as **GitNexus** (4325 symbols, 10556 relationships, 300 execution flows)
 | `gitnexus://repo/GitNexus/clusters` | All functional areas |
 | `gitnexus://repo/GitNexus/processes` | All execution flows |
 | `gitnexus://repo/GitNexus/process/{name}` | Step-by-step execution trace |
+| `gitnexus://group/{name}/contracts` | Group Contract Registry (provider/consumer rows + cross-links) |
+| `gitnexus://group/{name}/status` | Per-member index + Contract Registry staleness report |
 
 ## Self-Check Before Finishing
 

ARCHITECTURE.md

@@ -42,10 +42,14 @@ Monorepo: **CLI/MCP** (`gitnexus/`) + **browser UI** (`gitnexus-web/`).
 | `tool_map` | MCP/RPC tool definitions and handlers |
 | `shape_check` | Response shape vs consumer property access mismatches |
 | `group_list` | List repo groups or details for one group |
-| `group_query` | Cross-repo search in a group (reciprocal rank fusion) |
-| `group_sync` | Rebuild group Contract Registry (`contracts.json`) |
-| `group_contracts` | Inspect group contracts and cross-links |
-| `group_status` | Index and Contract Registry staleness per repo in a group |
+| `group_sync` | Rebuild group Contract Registry (`contracts.json`) and bridge graph |
+
+`query`, `context`, and `impact` are group-aware: pass `repo: "@<groupName>"` (or `"@<groupName>/<memberPath>"` to scope to one member) plus optional `service: "<monorepo/path>"`. Group-mode `query` merges per-repo results via Reciprocal Rank Fusion; group-mode `impact` runs the local walk in the chosen member and fans out across boundaries via the Contract Bridge (`gitnexus/src/core/group/cross-impact.ts`). The previously-planned `group_query`, `group_context`, `group_impact`, `group_contracts`, `group_status` MCP tools are intentionally not introduced — group-level state is exposed via resources instead:
+
+| Resource URI | Purpose |
+|--------------|---------|
+| `gitnexus://group/{name}/contracts` | Contract Registry (provider/consumer rows + cross-links) |
+| `gitnexus://group/{name}/status` | Per-member index + Contract Registry staleness |
 
 ## Where to change what
 
@@ -55,6 +59,7 @@ Monorepo: **CLI/MCP** (`gitnexus/`) + **browser UI** (`gitnexus-web/`).
 | Parsing/graph construction | `src/core/ingestion/pipeline-phases/` + `pipeline.ts` |
 | Graph schema/DB | `src/core/lbug/` (`schema.ts`, `lbug-adapter.ts`) |
 | MCP tools/resources | `src/mcp/server.ts`, `tools.ts`, `resources.ts` |
+| Cross-repo groups (sync, contracts, `@<group>` routing) | `src/core/group/` (`service.ts`, `cross-impact.ts`, `sync.ts`, `bridge-db.ts`) |
 | Search ranking | `src/core/search/` (BM25, hybrid fusion) |
 | Embeddings | `src/core/embeddings/` + `src/core/run-analyze.ts` |
 | Wiki generation | `src/core/wiki/` |