fix: address cubic review — avoid double blank line in validate output

Cubic flagged `altimate_core_validate`'s no-schema note: when the note was
pushed into the `lines` array, its leading `\n\n` combined with the `\n`
join produced three consecutive newlines in the rendered output. Fixed by
storing the note without the leading blanks and inserting an explicit
empty line at each call site.

Also:
- Extracted the warning to a module-level `NO_SCHEMA_NOTE` constant so
  the text lives in one place.
- Added regression tests that assert the rendered output never contains
  three consecutive newlines for either the valid or the failure path.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: anandgupta42

packages/opencode/src/altimate/tools/altimate-core-validate.ts

@@ -74,20 +74,31 @@ function classifyValidationError(message: string): string {
   return "validation_error"
 }
 
+// Warning appended when validation runs without a schema. Stored without a
+// leading blank so it can be pushed into a line array; a blank line is added
+// explicitly at each call site where spacing is desired.
+const NO_SCHEMA_NOTE =
+  "Note: No schema was provided, so table/column existence checks were skipped. " +
+  "To catch missing tables or columns, run `schema_inspect` on the referenced tables first " +
+  "or pass `schema_context` inline with {tables: {...}}."
+
 function formatValidate(data: Record<string, any>, hasSchema: boolean): string {
   if (data.error) return `Error: ${data.error}`
-  const schemaNote = hasSchema
-    ? ""
-    : "\n\nNote: No schema was provided, so table/column existence checks were skipped. " +
-      "To catch missing tables or columns, run `schema_inspect` on the referenced tables first " +
-      "or pass `schema_context` inline with {tables: {...}}."
-  if (data.valid) return `SQL is valid.${schemaNote}`
+  if (data.valid) {
+    return hasSchema ? "SQL is valid." : `SQL is valid.\n\n${NO_SCHEMA_NOTE}`
+  }
 
   const lines = ["Validation failed:\n"]
   for (const err of data.errors ?? []) {
     lines.push(`  • ${err.message}`)
     if (err.location) lines.push(`    at line ${err.location.line}`)
   }
-  if (schemaNote) lines.push(schemaNote)
+  if (!hasSchema) {
+    // Blank separator line, then the note — avoids the double newline that
+    // would appear if the note itself started with `\n\n` and was joined
+    // with `\n`.
+    lines.push("")
+    lines.push(NO_SCHEMA_NOTE)
+  }
   return lines.join("\n")
 }

packages/opencode/test/altimate/tools/altimate-core-validate.test.ts

@@ -133,6 +133,26 @@ describe("formatValidate", () => {
     expect(result).toContain("syntax error")
     expect(result).toContain("No schema was provided")
   })
+
+  test("no double blank line between valid SQL and the schema note", () => {
+    // Regression: previously the note started with `\n\n` which produced
+    // `SQL is valid.\n\n\n\nNote:` when concatenated. One blank separator is
+    // enough.
+    const result = formatValidate({ valid: true }, false)
+    expect(result).not.toContain("\n\n\n")
+  })
+
+  test("no extra blank line between failure list and the schema note", () => {
+    // Regression: pushing a note that starts with `\n\n` into the `lines`
+    // array and joining on `\n` produced three consecutive newlines.
+    const result = formatValidate(
+      { valid: false, errors: [{ message: "missing column foo" }] },
+      false,
+    )
+    expect(result).toContain("missing column foo")
+    expect(result).toContain("No schema was provided")
+    expect(result).not.toContain("\n\n\n")
+  })
 })
 
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