fix(ops): stop the replica field parser reading the next line

The panel reported "Error SQL: Replicate_Ignore_Server_Ids:" against a
replica that was healthy — both threads running, zero lag.

`\s` matches newlines in JavaScript, so `^\s*NAME:\s*(.*)$` let the `\s*`
after the colon walk past an EMPTY field's line break and capture the
following line. Last_SQL_Error is blank on a healthy replica and
Replicate_Ignore_Server_Ids happens to be printed immediately after it, so
the blank error field returned the next field's name as its value. Every
empty field was affected; the visible damage was that a healthy replica
rendered as broken, which is the worst direction for a health panel to fail.

Fixed with `[^\S\n]` — horizontal whitespace only — on both sides of the
field name.

Extracted as replicaField() and pinned by replication.spec.ts against the
verbatim output of the live replica, keeping the empty Last_SQL_Error
adjacent to Replicate_Ignore_Server_Ids because that exact adjacency is what
broke. Also covers the literal "NULL" lag surviving as a distinct value from
empty, and a field name that is a suffix of another (Last_Error vs
Last_SQL_Error) not matching the wrong line.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/api/src/ops/replication.service.ts

@@ -100,11 +100,7 @@ export class ReplicationService {
       return { ...empty, configured: true, problem: `No se pudo conectar: ${msg}` };
     }
 
-    const field = (name: string): string | null => {
-      const m = raw.match(new RegExp(`^\\s*${name}:\\s*(.*)$`, "m"));
-      const v = m?.[1]?.trim();
-      return v === undefined || v === "" ? null : v;
-    };
+    const field = (name: string): string | null => replicaField(raw, name);
 
     // An empty result set means the server is not configured as a replica at
     // all — distinct from "configured but broken", and worth saying plainly.
@@ -151,3 +147,25 @@ export class ReplicationService {
     };
   }
 }
+
+/**
+ * Read one field out of `SHOW REPLICA STATUS\G` output.
+ *
+ * Exported for testing, and worth testing: the obvious regex is wrong.
+ * `\s` matches newlines in JavaScript, so `^\s*NAME:\s*(.*)$` lets the `\s*`
+ * after the colon swallow the line break of an EMPTY field and capture the
+ * following line instead. Last_SQL_Error is empty on a healthy replica, so that
+ * version reported the next line ("Replicate_Ignore_Server_Ids:") as a SQL
+ * error and rendered a perfectly healthy replica as broken.
+ *
+ * Hence `[^\S\n]` — horizontal whitespace only — on both sides of the name.
+ *
+ * @returns the trimmed value, or null when the field is absent OR empty. Empty
+ *          and absent mean the same thing to every caller here: MySQL prints
+ *          error fields as blank rather than omitting them.
+ */
+export function replicaField(raw: string, name: string): string | null {
+  const m = raw.match(new RegExp(`^[^\\S\\n]*${name}:[^\\S\\n]*(.*)$`, "m"));
+  const v = m?.[1]?.trim();
+  return v === undefined || v === "" ? null : v;
+}