feat: design system v2 with liquid glass aesthetic

Overhaul design constants for OLED-first dark mode:
- Colors: brand palette, phase colors, glass/shadow tokens, gradients
- Typography: Inter font scale matching iOS type system
- Spacing: 4px base unit with layout constants
- Border radius: liquid glass card radii
- Animations: spring/timing presets for UI transitions

Add v2 product docs (PRD, PDD, BDSD) and update CLAUDE.md.
Install expo-video, expo-sharing, @expo-google-fonts/inter.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package-lock.json

@@ -8,6 +8,8 @@
       "name": "tabatago",
       "version": "1.0.0",
       "dependencies": {
+        "@expo-google-fonts/inter": "^0.4.2",
+        "@expo/ui": "~0.2.0-beta.9",
         "@expo/vector-icons": "^15.0.3",
         "@react-native-async-storage/async-storage": "^2.2.0",
         "@react-navigation/bottom-tabs": "^7.4.0",
@@ -24,10 +26,12 @@
         "expo-linear-gradient": "~15.0.8",
         "expo-linking": "~8.0.11",
         "expo-router": "~6.0.23",
+        "expo-sharing": "~14.0.8",
         "expo-splash-screen": "~31.0.13",
         "expo-status-bar": "~3.0.9",
         "expo-symbols": "~1.0.8",
         "expo-system-ui": "~6.0.9",
+        "expo-video": "~3.0.16",
         "expo-web-browser": "~15.0.10",
         "react": "19.1.0",
         "react-dom": "19.1.0",
@@ -1728,6 +1732,12 @@
         "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
       }
     },
+    "node_modules/@expo-google-fonts/inter": {
+      "version": "0.4.2",
+      "resolved": "https://registry.npmjs.org/@expo-google-fonts/inter/-/inter-0.4.2.tgz",
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+      "license": "MIT AND OFL-1.1"
+    },
     "node_modules/@expo/code-signing-certificates": {
       "version": "0.0.6",
       "resolved": "https://registry.npmjs.org/@expo/code-signing-certificates/-/code-signing-certificates-0.0.6.tgz",
@@ -2186,6 +2196,20 @@
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       "license": "MIT"
     },
+    "node_modules/@expo/ui": {
+      "version": "0.2.0-beta.9",
+      "resolved": "https://registry.npmjs.org/@expo/ui/-/ui-0.2.0-beta.9.tgz",
+      "integrity": "sha512-RaBcp0cMe5GykQogJwRZGy4o4JHDLtrr+HaurDPhwPKqVATsV0rR11ysmFe4QX8XWLP/L3od7NOkXUi5ailvaw==",
+      "license": "MIT",
+      "dependencies": {
+        "sf-symbols-typescript": "^2.1.0"
+      },
+      "peerDependencies": {
+        "expo": "*",
+        "react": "*",
+        "react-native": "*"
+      }
+    },
     "node_modules/@expo/vector-icons": {
       "version": "15.0.3",
       "resolved": "https://registry.npmjs.org/@expo/vector-icons/-/vector-icons-15.0.3.tgz",
@@ -6507,6 +6531,15 @@
         "node": ">=20.16.0"
       }
     },
+    "node_modules/expo-sharing": {
+      "version": "14.0.8",
+      "resolved": "https://registry.npmjs.org/expo-sharing/-/expo-sharing-14.0.8.tgz",
+      "integrity": "sha512-A1pPr2iBrxypFDCWVAESk532HK+db7MFXbvO2sCV9ienaFXAk7lIBm6bkqgE6vzRd9O3RGdEGzYx80cYlc089Q==",
+      "license": "MIT",
+      "peerDependencies": {
+        "expo": "*"
+      }
+    },
     "node_modules/expo-splash-screen": {
       "version": "31.0.13",
       "resolved": "https://registry.npmjs.org/expo-splash-screen/-/expo-splash-screen-31.0.13.tgz",
@@ -6565,6 +6598,17 @@
         }
       }
     },
+    "node_modules/expo-video": {
+      "version": "3.0.16",
+      "resolved": "https://registry.npmjs.org/expo-video/-/expo-video-3.0.16.tgz",
+      "integrity": "sha512-H1HlxcHGomZItqisGfW3YL/G9BHtNBfVSimDJcLuyxyU87wFnV8loO9tCjuhufkfh/aTa2sW5BYAjLjg9DvnBQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "expo": "*",
+        "react": "*",
+        "react-native": "*"
+      }
+    },
     "node_modules/expo-web-browser": {
       "version": "15.0.10",
       "resolved": "https://registry.npmjs.org/expo-web-browser/-/expo-web-browser-15.0.10.tgz",