Fix PDF font color not reflecting system settings via per-field merge

Root cause: resolveFontPrefsForUser() used `userRow ?? globalRow` whole-row
precedence. When an admin saved font settings with scope="global", only the
global row was updated. If the admin also had a user-scope row (created by
prior saves with the default scope="user"), ALL fields from the user-scope
row overrode the global row — including fontColor — causing the PDF to show
the old color even after changing global settings.

Schema change (executive-meetings.ts):
- Made fontFamily, fontSize, fontWeight, alignment, fontColor nullable.
  User-scope rows now store NULL for fields that inherit from global,
  and only store non-null values for fields the user explicitly overrode.

Backend fix (executive-meetings.ts):
- resolveFontPrefsForUser: per-field merge —
  user non-null → global non-null → schema default.
- PATCH handler for user-scope: after upsert, compares each field with the
  current global values. Fields matching global are set to NULL (= inherit).
  The post-nullification row is returned in the API response and audit log.
- No user-scope rows are deleted; scope isolation is preserved.

Frontend fix (executive-meetings.tsx):
- effectiveFont computed via per-field merge (u?.field ?? g?.field ?? default)
- FontSettingsResponse type updated for nullable fields (FontSettingsRow)
- Scope switching in FontSettingsSection loads the selected scope's values
  (global → globalFont ?? DEFAULT_FONT; user → effective font)
- globalFont prop threaded through SettingsSection → FontSettingsSection

Data migration: existing user-scope rows normalized via SQL — fields matching
global values set to NULL so per-field inheritance applies immediately.

Verified: TypeScript clean, e2e Playwright test passes, API tests confirm
per-field merge, nullification, and PDF color propagation.

artifacts/api-server/src/routes/executive-meetings.ts

@@ -2556,9 +2556,9 @@ router.delete(
 // PDF GENERATION (server-side)
 // =====================================================================
 
-// Resolve the user's effective font preferences exactly the way the
-// frontend does: user-scope row wins, otherwise global, otherwise the
-// schema defaults.
+// Resolve the user's effective font preferences via per-field merge:
+// user-scope value (if non-null) → global value (if non-null) → schema default.
+// User-scope rows store NULL for fields that inherit from global.
 async function resolveFontPrefsForUser(
   userId: number,
 ): Promise<{ font: PdfFontPrefs; logoObjectPath: string | null }> {
@@ -2576,16 +2576,14 @@ async function resolveFontPrefsForUser(
     );
   const userRow = rows.find((r) => r.scope === "user" && r.userId === userId);
   const globalRow = rows.find((r) => r.scope === "global");
-  const eff = userRow ?? globalRow;
   return {
     font: {
-      fontFamily: eff?.fontFamily ?? "system",
-      fontSize: eff?.fontSize ?? 14,
-      fontWeight: (eff?.fontWeight as PdfFontPrefs["fontWeight"]) ?? "regular",
-      alignment: (eff?.alignment as PdfFontPrefs["alignment"]) ?? "start",
-      fontColor: eff?.fontColor ?? "#000000",
+      fontFamily: (userRow?.fontFamily ?? globalRow?.fontFamily ?? "system") as string,
+      fontSize: userRow?.fontSize ?? globalRow?.fontSize ?? 14,
+      fontWeight: (userRow?.fontWeight ?? globalRow?.fontWeight ?? "regular") as PdfFontPrefs["fontWeight"],
+      alignment: (userRow?.alignment ?? globalRow?.alignment ?? "start") as PdfFontPrefs["alignment"],
+      fontColor: userRow?.fontColor ?? globalRow?.fontColor ?? "#000000",
     },
-    // Logo is global-scope only.
     logoObjectPath: globalRow?.logoObjectPath ?? null,
   };
 }
@@ -2970,15 +2968,33 @@ const upsertFontSettingsHandler = async (
           });
       }
     }
-    if (data.scope === "global") {
-      await tx
-        .delete(executiveMeetingFontSettingsTable)
+    if (data.scope === "user") {
+      const [curGlobal] = await tx
+        .select()
+        .from(executiveMeetingFontSettingsTable)
         .where(
           and(
-            eq(executiveMeetingFontSettingsTable.scope, "user"),
-            eq(executiveMeetingFontSettingsTable.userId, userId),
+            eq(executiveMeetingFontSettingsTable.scope, "global"),
+            isNull(executiveMeetingFontSettingsTable.userId),
           ),
         );
+      if (curGlobal && row) {
+        const nullIfSame = <T>(userVal: T, globalVal: T): T | null =>
+          userVal === globalVal ? null : userVal;
+        const nullified = {
+          fontFamily: nullIfSame(row.fontFamily, curGlobal.fontFamily),
+          fontSize: nullIfSame(row.fontSize, curGlobal.fontSize),
+          fontWeight: nullIfSame(row.fontWeight, curGlobal.fontWeight),
+          alignment: nullIfSame(row.alignment, curGlobal.alignment),
+          fontColor: nullIfSame(row.fontColor, curGlobal.fontColor),
+        };
+        const [updated] = await tx
+          .update(executiveMeetingFontSettingsTable)
+          .set(nullified)
+          .where(eq(executiveMeetingFontSettingsTable.id, row.id))
+          .returning();
+        row = updated;
+      }
     }
     await logAudit(tx, {
       action: existing ? "update" : "create",