feat(cv-v2): migrate Panel preset (#62)

Ports the legacy Panel CV preset (PanelCvTemplateComposer stacked
layout) onto the v2 layered architecture. The preset reads as four
equal-width panels of the same shell:

* Header card — pale-teal fill, centred Poppins UPPERCASE name,
  optional job title, centred meta + link line. Name paragraph is
  inlined instead of going through Headline.uppercaseCentered because
  that widget rewrites the card's padding via host.padding(...) which
  otherwise leaks into a visibly wider header outline.
* Profile card — full-width white card with UPPERCASE teal title,
  bronze-like teal accent strip, and the summary paragraph.
* Two-column row — left card stacks Skills + Education + Additional,
  right card stacks Experience + Projects. Each card is its own panel
  with the shared shell.
* All cards (header, profile, side modules) share a single
  CardWidget.Style: stroke 0.45pt, padding(bannerInnerPadding=8),
  cornerRadius(7). Only fillColor differs (header tinted teal vs
  panels white).

Section widths are anchored explicitly. v2 engine sections default to
fit-content widths inside a vertical column, so a card with long
content (Skills) would otherwise render visibly wider than a card
with short content (Education). The new widthAnchor(card, width)
helper drops a zero-height spacer of the pre-computed target width as
the card's first element, pinning every panel to identical outer
widths regardless of paragraph length.

Body rendering uses a preset-local dispatcher because the engine bans
nested horizontal rows and the side cards sit inside flow.addRow.
EntriesSection headers therefore use EntryCompactRenderer.titleDateBody
(single 'title - date' paragraph) instead of the standard
EntryRenderer's 2-column Row header.

Theme additions are additive:
* CvPalette.panel() — body slate ink, pale teal stroke + banner fill.
* CvTypography.panel() — Poppins/Lato 22/8.9/10.4/9.4/9.4/9.0/9.4 1.2.
* CvSpacing.panel() — 6pt page-flow gap, 8pt card padding, 2.2pt
  accent strip, 7pt corner radius.
* CvTheme.panel() factory wires the three above with the classic
  decoration.

CardWidget gains a PageFlowBuilder overload so top-level cards
(Profile) can be rendered directly under PageFlowBuilder without an
intermediate wrapper section. The applyStyle path is shared between
both render() overloads.

Tests:
* CvV2VisualParityTest now exercises 11 presets (added Panel); 11/11
  pass at the existing 50k pixel-diff budget against the new
  visual-baselines/cv-v2-layered/panel-page-0.png baseline (single
  page).
* PanelSmokeTest covers stable identity + default-factory and
  custom-theme render paths.

Author: DemchaAV

examples/src/main/java/com/demcha/examples/templates/cv/v2/CvPanelExample.java

@@ -0,0 +1,49 @@
+package com.demcha.examples.templates.cv.v2;
+
+import com.demcha.compose.GraphCompose;
+import com.demcha.compose.document.api.DocumentPageSize;
+import com.demcha.compose.document.api.DocumentSession;
+import com.demcha.compose.document.templates.api.DocumentTemplate;
+import com.demcha.compose.document.templates.cv.v2.data.CvDocument;
+import com.demcha.compose.document.templates.cv.v2.presets.Panel;
+import com.demcha.examples.support.ExampleDataFactory;
+import com.demcha.examples.support.ExampleOutputPaths;
+
+import java.nio.file.Path;
+
+/**
+ * Renders the v2 Panel CV preset against the shared grouped skills
+ * sample data — pale-teal header card with centred Poppins masthead,
+ * full-width Profile panel, two-column row pairing Skills + Education
+ * on the left with Experience + Projects on the right, and a closing
+ * Additional panel.
+ *
+ * <p>Output:
+ * {@code examples/target/generated-pdfs/templates/cv/cv-panel-v2.pdf}.</p>
+ */
+public final class CvPanelExample {
+
+    private CvPanelExample() {
+    }
+
+    public static Path generate() throws Exception {
+        Path outputFile = ExampleOutputPaths.prepare(
+                "templates/cv", "cv-panel-v2.pdf");
+        CvDocument doc = ExampleDataFactory.sampleCvDocumentV2();
+        DocumentTemplate<CvDocument> template = Panel.create();
+
+        float m = (float) Panel.RECOMMENDED_MARGIN;
+        try (DocumentSession document = GraphCompose.document(outputFile)
+                .pageSize(DocumentPageSize.A4)
+                .margin(m, m, m, m)
+                .create()) {
+            template.compose(document, doc);
+            document.buildPdf();
+        }
+        return outputFile;
+    }
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("Generated: " + generate());
+    }
+}

src/main/java/com/demcha/compose/document/templates/cv/v2/presets/Panel.java

@@ -123,6 +123,23 @@ public static CvPalette editorialBlue() {
                 DocumentColor.rgb(193, 201, 211));
     }
 
+    /**
+     * Panel palette ported from the v1 {@code PanelCvTemplateComposer}
+     * (ProductLeader tokens): body slate ink, slightly lighter slate
+     * for italic subtitles, the pale teal stroke used by every panel
+     * border, and the pale teal header card fill. The deeper header
+     * navy (rgb(20,44,66)), teal accent (rgb(0,128,128)), and white
+     * panel fill are preset-local because they are the fifth/sixth/
+     * seventh tokens — other v2 presets do not share them today.
+     */
+    public static CvPalette panel() {
+        return new CvPalette(
+                DocumentColor.rgb(54, 68, 84),     // ink — V1 BODY_TEXT/HEADER_META slate
+                DocumentColor.rgb(105, 117, 132),  // muted — slightly lighter slate
+                DocumentColor.rgb(179, 214, 211),  // rule — V1 PANEL_STROKE pale teal
+                DocumentColor.rgb(231, 246, 244)); // banner — V1 HEADER_FILL pale teal
+    }
+
     /**
      * Executive palette ported from the v1 {@code ExecutiveSlateCvTemplate}:
      * mid-slate body ink, soft muted slate for italic subtitles, the

src/main/java/com/demcha/compose/document/templates/cv/v2/theme/CvPalette.java

@@ -279,6 +279,30 @@ public static CvSpacing editorialBlue() {
                 3.0);                                    // entrySeparation
     }
 
+    /**
+     * Spacing for the Panel preset: card-led layout that has to fit
+     * Header / Profile / two-column row / Additional on one A4 page,
+     * so paddings and inter-card gaps are tight by design. Corner
+     * radius and accent rule width match the V1 ProductLeader tokens.
+     */
+    public static CvSpacing panel() {
+        return new CvSpacing(
+                6,                                       // pageFlowSpacing (tight inter-card gap)
+                3,                                       // sectionBodySpacing (inside a card)
+                DocumentInsets.zero(),                   // sectionBodyPadding (the card supplies its own padding)
+                DocumentInsets.zero(),                   // headlinePadding
+                DocumentInsets.zero(),                   // contactPadding
+                7.0,                                     // bannerCornerRadius (V1 CORNER_RADIUS)
+                8.0,                                     // bannerInnerPadding (compact card padding)
+                DocumentInsets.zero(),                   // bannerMargin
+                2.2,                                     // accentRuleWidth (V1 ACCENT_HEIGHT)
+                1.0,                                     // paragraphMarginTop
+                8.0,                                     // entryHeaderRowSpacing
+                1.0,                                     // entryTitleWeight
+                0.45,                                    // entryDateWeight
+                2.0);                                    // entrySeparation
+    }
+
     /**
      * Spacing for the Executive preset: generous executive feel with
      * an 8pt page-flow rhythm, compact module bodies, and a 1.1pt

src/main/java/com/demcha/compose/document/templates/cv/v2/theme/CvSpacing.java

@@ -167,6 +167,21 @@ public static CvTheme editorialBlue() {
                 CvDecoration.classic());
     }
 
+    /**
+     * The "Panel" look — Poppins headlines + Lato body, pale teal
+     * header card and module panels with thin teal stroke, deep navy
+     * masthead text, and teal section headings with a small accent
+     * strip beneath each title. Visual signature ported from the v1
+     * {@code PanelCvTemplateComposer} (ProductLeader tokens).
+     */
+    public static CvTheme panel() {
+        return new CvTheme(
+                CvPalette.panel(),
+                CvTypography.panel(),
+                CvSpacing.panel(),
+                CvDecoration.classic());
+    }
+
     /**
      * The "Executive" look — Poppins masthead + Lato body, deep slate
      * primary, warm bronze accent on module headings and contact

src/main/java/com/demcha/compose/document/templates/cv/v2/theme/CvTheme.java

@@ -191,6 +191,26 @@ public static CvTypography editorialBlue() {
                 1.45);   // line spacing
     }
 
+    /**
+     * Poppins headline + Lato body scale ported from the v1
+     * {@code PanelCvTemplateComposer} (ProductLeader tokens): a 22pt
+     * uppercase name in the tinted header card, a 10.4pt section-title
+     * slot for the teal module headings, and a 9.4pt body with 1.2
+     * line spacing tuned for the dense card layout.
+     */
+    public static CvTypography panel() {
+        return new CvTypography(
+                FontName.POPPINS, FontName.LATO,
+                22.0,    // headline (centered uppercase name)
+                8.9,     // contact (V1 META_SIZE = body - 0.5)
+                10.4,    // banner / module title (V1 SECTION_SIZE)
+                9.4,     // entry title
+                9.4,     // entry date
+                9.0,     // entry subtitle (italic)
+                9.4,     // body (V1 BODY_SIZE)
+                1.2);    // line spacing
+    }
+
     /**
      * Poppins headline + Lato body scale ported from the v1
      * {@code ExecutiveSlateCvTemplate}: a 24pt uppercase masthead, a

src/main/java/com/demcha/compose/document/templates/cv/v2/theme/CvTypography.java

@@ -1,5 +1,6 @@
 package com.demcha.compose.document.templates.widgets;
 
+import com.demcha.compose.document.dsl.PageFlowBuilder;
 import com.demcha.compose.document.dsl.SectionBuilder;
 import com.demcha.compose.document.style.DocumentColor;
 import com.demcha.compose.document.style.DocumentCornerRadius;
@@ -31,21 +32,47 @@ public static void render(SectionBuilder parent,
         Style safeStyle = style == null ? Style.builder().build() : style;
 
         parent.addSection(name, card -> {
-            card.spacing(safeStyle.spacing())
-                    .padding(safeStyle.padding());
-            if (safeStyle.fillColor() != null) {
-                card.fillColor(safeStyle.fillColor());
-            }
-            if (safeStyle.stroke() != null) {
-                card.stroke(safeStyle.stroke());
-            }
-            if (safeStyle.cornerRadius() != null) {
-                card.cornerRadius(safeStyle.cornerRadius());
-            }
+            applyStyle(card, safeStyle);
+            content.accept(card);
+        });
+    }
+
+    /**
+     * Top-level overload — renders the card as a page-flow section so
+     * presets can place full-width cards directly under
+     * {@link PageFlowBuilder} without wrapping them in a parent
+     * section. Visual shell behaves identically to the
+     * {@link #render(SectionBuilder, String, Style, Consumer)}
+     * variant.
+     */
+    public static void render(PageFlowBuilder flow,
+                              String name,
+                              Style style,
+                              Consumer<SectionBuilder> content) {
+        Objects.requireNonNull(flow, "flow");
+        Objects.requireNonNull(content, "content");
+        Style safeStyle = style == null ? Style.builder().build() : style;
+
+        flow.addSection(name, card -> {
+            applyStyle(card, safeStyle);
             content.accept(card);
         });
     }
 
+    private static void applyStyle(SectionBuilder card, Style style) {
+        card.spacing(style.spacing())
+                .padding(style.padding());
+        if (style.fillColor() != null) {
+            card.fillColor(style.fillColor());
+        }
+        if (style.stroke() != null) {
+            card.stroke(style.stroke());
+        }
+        if (style.cornerRadius() != null) {
+            card.cornerRadius(style.cornerRadius());
+        }
+    }
+
     /**
      * Visual shell options for {@link CardWidget}.
      */

src/main/java/com/demcha/compose/document/templates/widgets/CardWidget.java

@@ -114,7 +114,10 @@ private static Stream<Arguments> presets() {
                         (Supplier<DocumentTemplate<CvDocument>>) CompactMono::create),
                 Arguments.of("executive",
                         Executive.RECOMMENDED_MARGIN,
-                        (Supplier<DocumentTemplate<CvDocument>>) Executive::create));
+                        (Supplier<DocumentTemplate<CvDocument>>) Executive::create),
+                Arguments.of("panel",
+                        Panel.RECOMMENDED_MARGIN,
+                        (Supplier<DocumentTemplate<CvDocument>>) Panel::create));
     }
 
     /**

src/test/java/com/demcha/compose/document/templates/cv/v2/presets/CvV2VisualParityTest.java

@@ -0,0 +1,90 @@
+package com.demcha.compose.document.templates.cv.v2.presets;
+
+import com.demcha.compose.GraphCompose;
+import com.demcha.compose.document.api.DocumentSession;
+import com.demcha.compose.document.style.DocumentInsets;
+import com.demcha.compose.document.templates.api.DocumentTemplate;
+import com.demcha.compose.document.templates.cv.v2.data.CvDocument;
+import com.demcha.compose.document.templates.cv.v2.data.CvIdentity;
+import com.demcha.compose.document.templates.cv.v2.data.EntriesSection;
+import com.demcha.compose.document.templates.cv.v2.data.ParagraphSection;
+import com.demcha.compose.document.templates.cv.v2.data.RowStyle;
+import com.demcha.compose.document.templates.cv.v2.data.RowsSection;
+import com.demcha.compose.document.templates.cv.v2.data.SkillsSection;
+import com.demcha.compose.document.templates.cv.v2.theme.CvTheme;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Smoke test for the v2 Panel preset. Covers the header card with
+ * optional job title + link row, plus the two-column row composition
+ * fed through {@link com.demcha.compose.document.templates.cv.v2.components.SectionLookup}
+ * and {@link com.demcha.compose.document.templates.cv.v2.components.SectionDispatcher}.
+ */
+class PanelSmokeTest {
+
+    @Test
+    void exposes_stable_identity() {
+        DocumentTemplate<CvDocument> template = Panel.create();
+        assertThat(template.id()).isEqualTo("panel");
+        assertThat(template.displayName()).isEqualTo("Panel");
+    }
+
+    @Test
+    void default_factory_renders_full_document() throws Exception {
+        renderAndAssertNonEmpty(Panel.create(), fullDocument());
+    }
+
+    @Test
+    void custom_theme_factory_renders() throws Exception {
+        renderAndAssertNonEmpty(Panel.create(CvTheme.panel()), fullDocument());
+    }
+
+    private static void renderAndAssertNonEmpty(
+            DocumentTemplate<CvDocument> template,
+            CvDocument doc) throws Exception {
+        try (DocumentSession session = GraphCompose.document()
+                .pageSize(420, 595)
+                .margin(DocumentInsets.of(18))
+                .create()) {
+            template.compose(session, doc);
+            assertThat(session.roots()).isNotEmpty();
+        }
+    }
+
+    private static CvDocument fullDocument() {
+        return CvDocument.builder()
+                .identity(CvIdentity.builder()
+                        .name("Jane", "Doe")
+                        .jobTitle("Product Lead")
+                        .contact("+44 0", "j@d.com", "London")
+                        .link("LinkedIn", "https://linkedin.com/in/jane-doe")
+                        .build())
+                .sections(
+                        new ParagraphSection("Professional Summary",
+                                "Builds **reliable** product platforms."),
+                        SkillsSection.builder("Technical Skills")
+                                .group("Languages", "Java 21", "Kotlin")
+                                .group("Testing", "JUnit 5", "AssertJ")
+                                .build(),
+                        EntriesSection.builder("Education & Certifications")
+                                .entry("MSc Computer Science",
+                                        "University of Manchester",
+                                        "2019-2021",
+                                        "Distinction.")
+                                .build(),
+                        RowsSection.builder("Projects", RowStyle.BULLETED_STACKED)
+                                .row("GraphCompose (Java, PDFBox)",
+                                        "Declarative PDF layout engine.")
+                                .build(),
+                        EntriesSection.builder("Professional Experience")
+                                .entry("Lead", "Acme", "2021-2024",
+                                        "Built rendering services.")
+                                .build(),
+                        RowsSection.builder("Additional Information", RowStyle.PLAIN)
+                                .row("Languages", "English, German")
+                                .build())
+                .build();
+    }
+}