style(ui): float auth/security cards to match mockup shadow language

Login/register, forgot-password, reset-password, verify-email, and the
2FA/sessions settings cards all used a bare MuiPaper (1px border, no
shadow) predating this session's theme foundation. MuiPaper itself
stays untouched (it's a lower-level primitive used too broadly across
the app -- menus, popovers -- to safely restyle globally), so these
specific card instances get the same explicit no-border/floating-shadow
treatment already applied screen-by-screen elsewhere this session.

Static shadow value again, not theme.vars.customShadows -- inline sx
callbacks execute against whatever theme is in context, and none of
this repo's tests wrap components in a ThemeProvider (see fc56f94).

job-tracker-ui/src/components/SessionsSettingsCard.tsx

@@ -85,7 +85,7 @@ export default function SessionsSettingsCard() {
   }
 
   return (
-    <Paper sx={{ mt: 2, p: 2 }}>
+    <Paper sx={{ mt: 2, p: 2.5, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
       <Typography variant="h6" sx={{ mb: 1 }}>
         {t("sessionsSectionTitle")}
       </Typography>

job-tracker-ui/src/components/TwoFactorSettingsCard.tsx

@@ -184,7 +184,7 @@ export default function TwoFactorSettingsCard() {
   const isRecoveryStep = flow === "enable-recovery" || flow === "regenerate-recovery";
 
   return (
-    <Paper sx={{ mt: 2, p: 2 }}>
+    <Paper sx={{ mt: 2, p: 2.5, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
       <Typography variant="h6" sx={{ mb: 1 }}>
         {t("twoFactorSectionTitle")}
       </Typography>

job-tracker-ui/src/views/ForgotPasswordPage.tsx

@@ -36,7 +36,7 @@ export default function ForgotPasswordPage() {
           "radial-gradient(1200px 700px at 20% 0%, rgba(79,140,255,0.14), transparent 55%), radial-gradient(900px 600px at 80% 20%, rgba(245,158,11,0.10), transparent 55%)",
       }}
     >
-      <Paper sx={{ width: "min(520px, 100%)", p: 3 }}>
+      <Paper sx={{ width: "min(520px, 100%)", p: 4, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
         <Typography variant="h5" sx={{ fontWeight: 900, mb: 0.5 }}>
           {t("forgotPasswordTitle")}
         </Typography>

job-tracker-ui/src/views/LoginPage.tsx

@@ -130,7 +130,7 @@ export default function LoginPage() {
           "radial-gradient(1200px 700px at 20% 0%, rgba(79,140,255,0.14), transparent 55%), radial-gradient(900px 600px at 80% 20%, rgba(245,158,11,0.10), transparent 55%)",
       }}
     >
-      <Paper sx={{ width: "min(520px, 100%)", p: 3 }}>
+      <Paper sx={{ width: "min(520px, 100%)", p: 4, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
         <Typography variant="h5" sx={{ fontWeight: 900, mb: 0.5 }}>
           {t("signInTitle")}
         </Typography>

job-tracker-ui/src/views/ResetPasswordPage.tsx

@@ -40,7 +40,7 @@ export default function ResetPasswordPage() {
           "radial-gradient(1200px 700px at 20% 0%, rgba(79,140,255,0.14), transparent 55%), radial-gradient(900px 600px at 80% 20%, rgba(245,158,11,0.10), transparent 55%)",
       }}
     >
-      <Paper sx={{ width: "min(520px, 100%)", p: 3 }}>
+      <Paper sx={{ width: "min(520px, 100%)", p: 4, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
         <Typography variant="h5" sx={{ fontWeight: 900, mb: 0.5 }}>
           {t("resetPasswordTitle")}
         </Typography>

job-tracker-ui/src/views/VerifyEmailPage.tsx

@@ -48,7 +48,7 @@ export default function VerifyEmailPage() {
           "radial-gradient(1200px 700px at 20% 0%, rgba(79,140,255,0.14), transparent 55%), radial-gradient(900px 600px at 80% 20%, rgba(245,158,11,0.10), transparent 55%)",
       }}
     >
-      <Paper sx={{ width: "min(520px, 100%)", p: 3 }}>
+      <Paper sx={{ width: "min(520px, 100%)", p: 4, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
         <Typography variant="h5" sx={{ fontWeight: 900, mb: 0.5 }}>
           {t("verifyEmailTitle")}
         </Typography>