Restore GraphQL schema merge for Relay query text

relay-compiler requires a single schema file: a directory is rejected
and schemaExtensions marks fields as client-only, so it emitted
text: null and the console posted query: null, getting a 400 on every
operation.

Restore the merge step (contrib/merge-graphql-schema.sh, the
RELAY_SCHEMAS make rules, and the gitignore entry) and point each
relay.config.json project back at the merged schema.graphql. The IDE
graphql-config removal and npm-script cleanup are unrelated and stay.

Signed-off-by: Émile Ré <emile@probo.com>

contrib/claude/make.md

@@ -41,7 +41,7 @@ Individual codegen is driven by `go generate`:
 - `go generate ./pkg/server/api/mcp/v1` — MCP (mcpgen)
 - `go generate ./pkg/llm` — LLM model registry from OpenRouter (`make genmodels`)
 
-`make relay` runs `relay-compiler`, which reads the split `.graphql` schema files directly (via each project's `schema` + `schemaExtensions` in `relay.config.json`) and keeps generated artifacts in sync (stale ones are removed automatically).
+`make relay` merges each service's split `.graphql` schema files into a single `schema.graphql` (via `contrib/merge-graphql-schema.sh`) and runs `relay-compiler`. The merge is required: relay-compiler's `schema` must be a single file, and `schemaExtensions` would mark the fields as client-only (emitting `text: null`), so the split files cannot be fed to Relay directly.
 
 ## Coverage
 

contrib/merge-graphql-schema.sh

@@ -0,0 +1,44 @@
+#!/bin/sh
+# Merge split GraphQL schema files into a single file for Relay.
+# Strips "type Mutation" and "extend type Mutation { ... }" blocks,
+# then appends a single "type Mutation { ... }" with all collected fields.
+#
+# Usage: merge-graphql-schema.sh <output> <graphql-dir>
+
+set -eu
+
+output="$1"
+graphql_dir="$2"
+base="$graphql_dir/base.graphql"
+
+mutation_fields=$(mktemp)
+schema_body=$(mktemp)
+trap 'rm -f "$mutation_fields" "$schema_body"' EXIT
+
+process_file() {
+    awk -v mf="$mutation_fields" '
+    /^type Mutation$/ { next }
+    /^(extend )?type Mutation \{/ { skip=1; depth=1; next }
+    skip {
+        if (/\{/) depth++
+        if (/\}/) { depth--; if (depth==0) { skip=0; next } }
+        if (skip) { print >> mf; next }
+    }
+    { print }
+    ' "$1"
+}
+
+{
+    process_file "$base"
+    for f in "$graphql_dir"/*.graphql; do
+        [ "$f" = "$base" ] && continue
+        process_file "$f"
+    done
+} > "$schema_body"
+
+{
+    cat "$schema_body"
+    printf '\ntype Mutation {\n'
+    cat "$mutation_fields"
+    printf '}\n'
+} > "$output"