feat(sql-editor): Data Peek polish + DB2 paging fix

.cursor/rules/sql-editor-agent-memory.mdc

@@ -28,19 +28,19 @@ FoxSchema = schema diff/migration + SQL Editor. Destinations checklist, Schema e
 - **Cell banding** in Monaco: `.fox-cell-band-sql` / `.fox-cell-band-code` + left edge.
 - **Statement strip**: Jupyter-like `In [n]:`, kind badge, per-cell **▶** → `execute({ statementIndices: [i] })`.
 - Toolbar Run still uses strip checkboxes / selection; per-cell Play ignores both.
-- Results side-by-side labels: `Out [n]: …` (`sql-result-stmt-${i}`).
+- Results labels: `Out [n]: …` (`sql-result-stmt-${i}` in side-by-side; By cred stacks Out grids vertically per credential).
 - Password / Safe-mode confirm preserve `statementIndices` on resume.
 
-### 1. Data peek (Cmd/Ctrl-click)
-- **UI**: `DataPeekPanel.tsx` — modal grids + breadcrumb; Esc closes.
-- **Trigger**: Schema explorer Cmd/Ctrl-click on TABLE / VIEW / MQT → `openDataPeek`.
-- **Queries**: `tablePreview.ts` builds SQL via `sqlTag` / `renderSqlQuery` (bound params, never string paste).
-  - `buildTablePreview` → `SELECT * FROM <quoted id>` (paging/cap from `/sql/execute`).
-  - `buildForeignKeyDrilldown` → parent WHERE with bound cell values; null if FK cols unusable.
-  - `foreignKeyLinksFor` — case-insensitive column match (Oracle/Db2 fold).
-- **Drill**: FK cell click → `drillDataPeek` stacks another grid; use **row index** (not 1-based display #).
-- **Store**: `useSqlEditorStore` `dataPeek` / `openDataPeek` / `drillDataPeek` / `closeDataPeek` / `closeDataPeekFrom`.
-- Match drilled table names both qualified (`public.customers`) and bare against schema cache.
+### 1. Data peek (Cmd/Ctrl-click + result FK)
+- **UI**: `DataPeekPanel.tsx` — modal grids; Esc closes. Each panel: WHERE / ORDER BY / LIMIT + drag resize + arrange grip. Mounted from `SqlEditorView` (not only Schema).
+- **Triggers**:
+  - Schema explorer Cmd/Ctrl-click TABLE / VIEW / MQT → `openDataPeek`.
+  - Editor result FK cell (rust underline) → `openDataPeekFromFk` (`ResultsPanel` / `foreignKeyLinksForSql`).
+- **Queries**: `tablePreview.ts` — `buildTablePreview`, `buildForeignKeyDrilldown`, `composePeekSql`, `foreignKeyLinksFor` / `foreignKeyLinksForSql` / `tablesFromSql`.
+- **Drill**: FK cell → `drillDataPeek` stacks panels (`drillKey` siblings); use **row index**.
+- **Store**: `dataPeek` / `openDataPeek` / `openDataPeekFromFk` / `drillDataPeek` / `updateDataPeekFilters` / `pageDataPeekEntry` / `reorderDataPeekEntries` / `setDataPeekPanelHeight` / close APIs.
+- **FK color**: `--fox-grid-link` rust `#9a3412` + solid underline.
+- Match drilled table names both qualified and bare against schema cache.
 
 ### 2. Node `sql` bridge (`-- @node` / `-- @nodets`)
 **Design**: worker has **no DB handle**. Cell calls `sql\`...\``; worker renders to `{ text, params }` and posts `cell-query` to the API parent; parent runs SQL and replies `cell-query-result`.

CONTRIBUTING.md

@@ -121,7 +121,13 @@ A few rules that have bitten people before (the full set is in [CLAUDE.md](CLAUD
 1. Branch off `main`.
 2. Keep the change focused; update docs and tests alongside code.
 3. Ensure the correctness gates pass (`tsc --noEmit` + `vitest run`).
-4. Write a clear PR description: what changed, why, and how you verified it.
+4. Write a **short, user-facing** PR description: what the user gets, why it
+   matters, and how you verified it. Prefer a limited summary on GitHub — do
+   **not** paste long internal implementation plans, agent transcripts, or
+   speculative design dumps into public PR bodies.
+5. Keep copyright / `NOTICE` / `LICENSE` intact. Prefer the SPDX header in
+   [docs/COPYRIGHT_HEADER.txt](docs/COPYRIGHT_HEADER.txt) on new source files.
+   Authorship: Huy Phan `<huyplb@gmail.com>` (see [NOTICE](NOTICE)).
 
 Bug reports and feature ideas → open a GitHub issue. Security vulnerabilities →
 **do not** open a public issue; follow [SECURITY.md](SECURITY.md).

LICENSE

@@ -180,7 +180,8 @@ END OF TERMS AND CONDITIONS
 ## Copyright Notice
 
 ```
-Copyright 2026 huyplb
+Copyright 2024-2026 Huy Phan <huyplb@gmail.com>
+Copyright 2024-2026 tedious-code contributors
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -195,16 +196,19 @@ See the License for the specific language governing permissions and
 limitations under the License.
 ```
 
+Also see the project root `NOTICE` file.
+
 ---
 
 ## How to Apply This License to Your Files
 
-Add the following boilerplate notice at the top of each source file:
+Add the following boilerplate notice at the top of each source file
+(also in `docs/COPYRIGHT_HEADER.txt`):
 
 ```
 /*
- * foxSchema
- * Copyright 2026 huyplb@gmail.com
+ * Fox Schema (foxschema)
+ * Copyright 2024-2026 Huy Phan <huyplb@gmail.com>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -217,6 +221,8 @@ Add the following boilerplate notice at the top of each source file:
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
  */
 ```
 

NOTICE

@@ -0,0 +1,15 @@
+Fox Schema (foxschema)
+Copyright 2024-2026 Huy Phan <huyplb@gmail.com>
+Copyright 2024-2026 tedious-code contributors
+
+This product includes software developed by Huy Phan and contributors
+to the Fox Schema project (https://github.com/tedious-code/foxschema).
+
+Licensed under the Apache License, Version 2.0.
+See the LICENSE file in the project root for full license text.
+
+Attribution notice
+------------------
+Redistribution or reuse of this work must retain copyright notices and
+the Apache License terms. Removing copyright, NOTICE, or LICENSE files
+to conceal authorship is not permitted under the License.

README.md

@@ -111,4 +111,8 @@ Maintainers: [docs/PUBLISH.md](docs/PUBLISH.md) · [docs/ARCHITECTURE.md](docs/A
 
 ## License
 
-Apache-2.0
+Copyright 2024–2026 Huy Phan `<huyplb@gmail.com>` and [tedious-code](https://github.com/tedious-code)
+contributors. See [NOTICE](NOTICE) and [LICENSE](LICENSE) (Apache-2.0).
+
+Keep copyright / NOTICE / LICENSE when you fork or redistribute — stripping
+authorship notices is not allowed under the License.

apps/web/src/backend/api/sql-execute.test.ts

@@ -180,7 +180,8 @@ describe('runStatements against a real SQLite file', () => {
         expect(results[0].error).toMatch(/wrap boom/);
       }
       expect(spy).toHaveBeenCalledTimes(1);
-      expect(String(spy.mock.calls[0]![2])).toContain('_fox_page');
+      expect(String(spy.mock.calls[0]![2])).toContain('fox_page');
+      expect(String(spy.mock.calls[0]![2])).not.toContain('_fox_page');
     } finally {
       spy.mockRestore();
     }

apps/web/src/backend/api/sql-execute.ts

@@ -144,8 +144,8 @@ export async function runStatements(
         continue;
       }
 
+      const paged = wrapSqlForPage(sql, dialect, offset, maxRows);
       try {
-        const paged = wrapSqlForPage(sql, dialect, offset, maxRows);
         const raw = await ConnectionFactory.executeOnConnection<Record<string, unknown>>(
           dialect,
           connection,
@@ -167,7 +167,9 @@ export async function runStatements(
         const wrapMsg = error instanceof Error ? error.message : String(error);
         // Fail closed for all pageable statements: raw fallback can materialize
         // an unbounded result set before shapeRows truncates, and ignores OFFSET.
-        pushErr(`Paging failed: ${wrapMsg}`);
+        // Include the wrapped SQL so DB2 alias / dialect issues are diagnosable.
+        const preview = paged.length > 240 ? `${paged.slice(0, 240)}…` : paged;
+        pushErr(`Paging failed: ${wrapMsg}\nWrapped SQL: ${preview}`);
       }
     }
     return results;

apps/web/src/backend/api/sql-page-wrap.test.ts

@@ -9,10 +9,18 @@ import {
 describe('sql-page-wrap', () => {
   it('wraps postgres-style with LIMIT/OFFSET and +1 probe', () => {
     expect(wrapSqlForPage('SELECT 1;', 'postgres', 40, 20)).toBe(
-      'SELECT * FROM (SELECT 1) AS _fox_page LIMIT 21 OFFSET 40'
+      'SELECT * FROM (SELECT 1) AS fox_page LIMIT 21 OFFSET 40'
     );
   });
 
+  it('wraps db2 without a leading-underscore alias (SQL20521N)', () => {
+    const sql = wrapSqlForPage('select * from USER order by id DESC', 'db2', 0, 200);
+    expect(sql).toBe(
+      'SELECT * FROM (select * from USER order by id DESC) AS fox_page OFFSET 0 ROWS FETCH FIRST 201 ROWS ONLY'
+    );
+    expect(sql).not.toMatch(/_fox_page/);
+  });
+
   it('wraps sqlserver without ORDER BY using dummy ORDER BY + OFFSET FETCH', () => {
     const sql = wrapSqlForPage('SELECT id FROM t', 'sqlserver', 0, 10);
     expect(sql).toContain('OFFSET 0 ROWS FETCH NEXT 11 ROWS ONLY');

apps/web/src/backend/api/sql-page-wrap.ts

@@ -1,6 +1,13 @@
 /**
+ * Fox Schema (foxschema)
+ * Copyright 2024-2026 Huy Phan <huyplb@gmail.com>
+ * SPDX-License-Identifier: Apache-2.0
+ *
  * Wrap a statement so the engine returns a page (LIMIT/OFFSET).
  * Fetches `limit + 1` rows so the caller can detect `hasNext` without a COUNT.
+ *
+ * Alias must not start with `_` — DB2 treats `_…` as a conditional-compilation
+ * directive (SQL20521N). Keep a plain letter-led name for all dialects.
  */
 
 import { statementVerb } from '@foxschema/core';
@@ -11,6 +18,9 @@ const PAGEABLE_VERBS = new Set(['select', 'values']);
 /** Dialects that use T-SQL OFFSET/FETCH (not MySQL/Postgres LIMIT). */
 const TSQL_DIALECTS = new Set(['sqlserver', 'mssql', 'azuresql']);
 
+/** Derived-table alias for page wraps (no leading underscore — see file header). */
+const PAGE_ALIAS = 'fox_page';
+
 export function clampOffset(v: unknown): number {
   const n = typeof v === 'number' ? Math.floor(v) : Number.NaN;
   if (!Number.isFinite(n) || n < 0) return 0;
@@ -135,16 +145,16 @@ export function wrapSqlForPage(
     if (hasTopLevelOrderBy(inner)) {
       return `${inner} ${fetch}`;
     }
-    return `SELECT * FROM (${inner}) AS _fox_page ORDER BY (SELECT NULL) ${fetch}`;
+    return `SELECT * FROM (${inner}) AS ${PAGE_ALIAS} ORDER BY (SELECT NULL) ${fetch}`;
   }
   if (d === 'oracle') {
-    return `SELECT * FROM (${inner}) _fox_page OFFSET ${offset} ROWS FETCH NEXT ${fetchLimit} ROWS ONLY`;
+    return `SELECT * FROM (${inner}) ${PAGE_ALIAS} OFFSET ${offset} ROWS FETCH NEXT ${fetchLimit} ROWS ONLY`;
   }
   if (d === 'db2') {
-    return `SELECT * FROM (${inner}) AS _fox_page OFFSET ${offset} ROWS FETCH FIRST ${fetchLimit} ROWS ONLY`;
+    return `SELECT * FROM (${inner}) AS ${PAGE_ALIAS} OFFSET ${offset} ROWS FETCH FIRST ${fetchLimit} ROWS ONLY`;
   }
   // Postgres, MySQL, MariaDB, SQLite, Cockroach, Yugabyte, TiDB, DuckDB, ClickHouse-ish
-  return `SELECT * FROM (${inner}) AS _fox_page LIMIT ${fetchLimit} OFFSET ${offset}`;
+  return `SELECT * FROM (${inner}) AS ${PAGE_ALIAS} LIMIT ${fetchLimit} OFFSET ${offset}`;
 }
 
 /** After shaping, drop the probe row and set truncated/hasNext. */

apps/web/src/frontend/components/sql-editor/DataGrid.tsx

@@ -1,3 +1,10 @@
+/**
+ * Fox Schema (foxschema)
+ * Copyright 2024-2026 Huy Phan <huyplb@gmail.com>
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Result DataGrid (paper surface, paging, FK drill links for Data Peek).
+ */
 import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { AlertTriangle, Download, GripVertical, RefreshCw } from 'lucide-react';
 import type { SqlStatementResult } from '../../api/sqlApi';
@@ -24,20 +31,20 @@ const LONG_TEXT_NAME =
 type CellKind = 'null' | 'number' | 'boolean' | 'datetime' | 'binary' | 'string';
 
 const KIND_CELL_CLASS: Record<CellKind, string> = {
-  null: 'italic text-[#94a3b8]',
-  number: 'text-[#1d4ed8]',
-  boolean: 'text-[#7c3aed]',
-  datetime: 'text-[#0f766e]',
-  binary: 'text-[#b45309]',
-  string: 'text-[#1e293b]',
+  null: 'italic text-[var(--fox-grid-muted)]',
+  number: 'tabular-nums text-[var(--fox-grid-number)] font-semibold',
+  boolean: 'text-[var(--fox-grid-boolean)]',
+  datetime: 'text-[var(--fox-grid-datetime)]',
+  binary: 'text-[var(--fox-grid-binary)]',
+  string: 'text-[var(--fox-grid-ink)]',
 };
 
 const KIND_HEADER_CLASS: Record<Exclude<CellKind, 'null'>, string> = {
-  number: 'text-[#1d4ed8]',
-  boolean: 'text-[#7c3aed]',
-  datetime: 'text-[#0f766e]',
-  binary: 'text-[#b45309]',
-  string: 'text-[#64748b]',
+  number: 'text-[var(--fox-grid-number)]',
+  boolean: 'text-[var(--fox-grid-boolean)]',
+  datetime: 'text-[var(--fox-grid-datetime)]',
+  binary: 'text-[var(--fox-grid-binary)]',
+  string: 'text-[var(--fox-grid-muted)]',
 };
 
 const KIND_LABEL: Record<Exclude<CellKind, 'null'>, string> = {
@@ -682,7 +689,8 @@ export const DataGrid: React.FC<{
                               // 1-based number shown in the # column and would
                               // read the NEXT row's value.
                               onClick={() => onLinkClick?.(colIdx, i)}
-                              className="underline decoration-dotted underline-offset-2 text-cyan-300 hover:text-cyan-200"
+                              // Rust ID color + solid underline — pale cyan was unreadable.
+                              className="underline decoration-solid underline-offset-2 decoration-2 decoration-[var(--fox-grid-link)] text-[var(--fox-grid-link)] font-bold hover:brightness-110"
                             >
                               {text}
                             </button>