Characters: build the page around Darragh Oakwanderer's sheet

Replaces the Characters placeholder with a real 5e character sheet
feature, following the same read-only-detail/edit-split/game-notes
pattern as NPCs and Enemies:

- Character entity: identity, combat vitals, six ability scores, saving
  throw and skill proficiencies (computed modifiers, not stored), a
  small attacks table, and the sheet's freeform boxes (features,
  equipment, personality, appearance, backstory, allies, treasure).
- Detail page shows the portrait uncropped, then the sheet - genuine
  <table>s for ability scores, skills and attacks, since that's the one
  part of a character sheet that actually is a table; everything else
  reuses the prose helpers from the enemy stat block. Game notes are
  the only editable field here, same as Enemy/NPC.
- Edit page covers every field via CharacterType; the attack rows are
  six plain inputs handled by hand (not a Symfony collection field),
  since it's a short fixed-shape table, not a dynamic list.
- Portraits follow the NPC convention: assets/image/characters/<NameNo
  Spaces>.png, computed path, not a DB column.
- Imported the example sheet from assets/characters/ (Darragh
  Oakwanderer, halfling ranger) directly into the database.

Tests: entity math (ability/save/skill modifiers, passive perception,
portrait path), template rendering for show/edit/index (catches broken
Twig/macro/path()/asset() calls), and the login-gate redirect. 21/21
passing; schema validate clean.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/Entity/CharacterTest.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace App\Tests\Entity;
+
+use App\Entity\Character;
+use PHPUnit\Framework\TestCase;
+
+class CharacterTest extends TestCase
+{
+    private function darragh(): Character
+    {
+        return (new Character())
+            ->setName('Darragh Oakwanderer')
+            ->setCharacterClass('Ranger')
+            ->setLevel(2)
+            ->setRace('Halfling, stout')
+            ->setProficiencyBonus(2)
+            ->setStrength(12)
+            ->setDexterity(17)
+            ->setWisdom(13)
+            ->setSavingThrowProficiencies(['Strength', 'Dexterity'])
+            ->setSkillProficiencies(['Sleight of Hand', 'Stealth']);
+    }
+
+    public function testAbilityModifierRoundsDown(): void
+    {
+        $c = new Character();
+
+        self::assertSame(-1, $c->abilityModifier(8));
+        self::assertSame(0, $c->abilityModifier(10));
+        self::assertSame(0, $c->abilityModifier(11));
+        self::assertSame(3, $c->abilityModifier(17));
+    }
+
+    public function testSkillModifierAddsProficiencyOnlyWhenProficient(): void
+    {
+        $c = $this->darragh();
+
+        // Dex 17 -> +3, proficient (+2 prof) -> +5
+        self::assertSame(5, $c->skillModifier('Stealth'));
+        // Wis 13 -> +1, not proficient in Perception
+        self::assertSame(1, $c->skillModifier('Perception'));
+    }
+
+    public function testSaveModifierAddsProficiencyOnlyWhenProficient(): void
+    {
+        $c = $this->darragh();
+
+        self::assertSame(3, $c->saveModifier('Strength'));   // Str +1, proficient +2 => +3
+        self::assertSame(5, $c->saveModifier('Dexterity'));  // Dex +3, proficient +2 => +5
+        self::assertSame(1, $c->saveModifier('Wisdom'));     // Wis +1, not proficient
+    }
+
+    public function testPassivePerceptionIsTenPlusPerceptionModifier(): void
+    {
+        $c = $this->darragh(); // Wis +1, not proficient in Perception
+
+        self::assertSame(11, $c->passivePerception());
+    }
+
+    public function testPortraitPathStripsSpacesFromName(): void
+    {
+        $c = (new Character())->setName('Darragh Oakwanderer');
+
+        self::assertSame('image/characters/DarraghOakwanderer.png', $c->getPortraitPath());
+    }
+
+    public function testMetaLineCombinesRaceClassAndLevel(): void
+    {
+        self::assertSame('Halfling, stout Ranger 2', $this->darragh()->getMetaLine());
+        self::assertSame('', (new Character())->getMetaLine());
+        self::assertSame('Halfling', (new Character())->setRace('Halfling')->getMetaLine());
+    }
+}