build(make): expose e2e-peer-visibility target + fix help filter for digit-containing names (task #166)

Wires the local peer-visibility MCP gate into the Makefile so a
developer can run it via `make e2e-peer-visibility` against an
already-up local prod-mimic stack (`make up`), without remembering the
bash path. This is the dev-side counterpart to the CI job added in
the same commit on this branch — together they close task #166's
"wire into local-E2E gate" ask.

The help-line grep regex didn't include digits, so the new
e2e-peer-visibility target was correctly defined but invisible to
`make help`. Adds [0-9] to the character class and widens the label
column to 22 chars so longer target names line up. Other targets are
unaffected.

NOT auto-merged (per task #166 instructions). See PR body for the
verification + the manual command for ad-hoc runs without the make
target.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Makefile

@@ -4,10 +4,10 @@
 # use this Makefile; CI calls docker compose / go test directly so the
 # Makefile can evolve without breaking the build.
 
-.PHONY: help dev up down logs build test
+.PHONY: help dev up down logs build test e2e-peer-visibility
 
 help: ## Show this help.
-	@grep -E '^[a-zA-Z_-]+:.*?## ' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-12s\033[0m %s\n", $$1, $$2}'
+	@grep -E '^[a-zA-Z0-9_-]+:.*?## ' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-22s\033[0m %s\n", $$1, $$2}'
 
 dev: ## Start the full stack with air hot-reload for the platform service.
 	docker compose -f docker-compose.yml -f docker-compose.dev.yml up
@@ -26,3 +26,13 @@ build: ## Force a fresh build of the platform image (no cache).
 
 test: ## Run Go unit tests in workspace-server/.
 	cd workspace-server && go test -race ./...
+
+# ─── Local prod-mimic E2E gates ────────────────────────────────────────
+# Run the LITERAL peer-visibility MCP list_peers gate against the
+# already-running local stack (`make up` or `make dev`). Same byte-
+# identical assertion as the staging gate — only provisioning differs.
+# Skips any runtime whose provider key is absent (partially-keyed env
+# is fine). See tests/e2e/test_peer_visibility_mcp_local.sh for the
+# env contract (CLAUDE_CODE_OAUTH_TOKEN / E2E_MINIMAX_API_KEY / etc).
+e2e-peer-visibility: ## Run the LOCAL peer-visibility MCP gate vs the running stack (needs `make up` first).
+	bash tests/e2e/test_peer_visibility_mcp_local.sh