feat: add horror prompt library with severity tiers and voice texts

tests/test_prompts.py

@@ -0,0 +1,61 @@
+from server.prompts import (
+    get_image_prompt,
+    get_voice_text,
+    get_direct_address_text,
+    SEVERITY_TIERS,
+)
+
+
+class TestImagePrompts:
+    def test_low_severity_prompt(self):
+        """Low severity returns abstract/atmospheric prompt."""
+        prompt = get_image_prompt(severity=0.5)
+        assert isinstance(prompt, str)
+        assert len(prompt) > 10
+
+    def test_high_severity_prompt(self):
+        """High severity returns more extreme prompt."""
+        prompt = get_image_prompt(severity=4.0)
+        assert isinstance(prompt, str)
+        assert len(prompt) > 10
+
+    def test_prompts_vary(self):
+        """Consecutive calls produce different prompts."""
+        prompts = [get_image_prompt(severity=2.0) for _ in range(10)]
+        assert len(set(prompts)) > 1
+
+    def test_severity_tiers_ordered(self):
+        """Tier thresholds are in ascending order."""
+        thresholds = [t[0] for t in SEVERITY_TIERS]
+        assert thresholds == sorted(thresholds)
+
+    def test_negative_prompt_included(self):
+        """Prompt includes SDXL negative prompt suffix."""
+        prompt = get_image_prompt(severity=1.0)
+        assert isinstance(prompt, str)
+
+
+class TestVoiceTexts:
+    def test_whisper_text(self):
+        """Get a whisper text fragment."""
+        text = get_voice_text()
+        assert isinstance(text, str)
+        assert len(text) > 0
+
+    def test_whisper_texts_vary(self):
+        """Consecutive calls produce different texts."""
+        texts = [get_voice_text() for _ in range(20)]
+        assert len(set(texts)) > 1
+
+
+class TestDirectAddress:
+    def test_direct_address_text(self):
+        """Get a direct address phrase."""
+        text = get_direct_address_text()
+        assert isinstance(text, str)
+        assert len(text) > 0
+
+    def test_direct_address_texts_vary(self):
+        """Consecutive calls produce different phrases."""
+        texts = [get_direct_address_text() for _ in range(20)]
+        assert len(set(texts)) > 1