Test add JSON schema for env vars

Not really sure if this'll be useful

env.schema.json

@@ -0,0 +1,84 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": ["PHANPY_WEBSITE", "PHANPY_CLIENT_NAME"],
+  "properties": {
+    "PHANPY_CLIENT_NAME": {
+      "type": "string",
+      "default": "Phanpy",
+      "minLength": 1,
+      "maxLength": 100,
+      "description": "Client name that affects web page title, app title, OpenGraph card title, and client name for authentication"
+    },
+    "PHANPY_WEBSITE": {
+      "type": "string",
+      "default": "https://phanpy.social",
+      "format": "uri",
+      "description": "Canonical URL of the website, affects OpenGraph card URL and client URL for authentication"
+    },
+    "PHANPY_DEFAULT_INSTANCE": {
+      "type": "string",
+      "pattern": "^(?!https?://).*$",
+      "format": "hostname",
+      "description": "Default instance for log-in (e.g. 'mastodon.social', without https://)"
+    },
+    "PHANPY_DEFAULT_INSTANCE_REGISTRATION_URL": {
+      "type": "string",
+      "format": "uri",
+      "description": "URL of the instance registration page (e.g. https://mastodon.social/auth/sign_up)"
+    },
+    "PHANPY_PRIVACY_POLICY_URL": {
+      "type": "string",
+      "format": "uri",
+      "description": "URL of the privacy policy page"
+    },
+    "PHANPY_DEFAULT_LANG": {
+      "type": "string",
+      "minLength": 2,
+      "maxLength": 10,
+      "description": "Default language fallback after multiple detection methods"
+    },
+    "PHANPY_REFERRER_POLICY": {
+      "type": "string",
+      "default": "origin",
+      "enum": [
+        "no-referrer",
+        "no-referrer-when-downgrade",
+        "origin",
+        "origin-when-cross-origin",
+        "same-origin",
+        "strict-origin",
+        "strict-origin-when-cross-origin",
+        "unsafe-url"
+      ],
+      "description": "Referrer policy for the site, applied with meta tag on client-side"
+    },
+    "PHANPY_LINGVA_INSTANCES": {
+      "type": "string",
+      "separator": " ",
+      "deprecated": true,
+      "description": "DEPRECATED: Space-separated list of Lingva instances for translation"
+    },
+    "PHANPY_TRANSLANG_INSTANCES": {
+      "type": "string",
+      "separator": " ",
+      "default": "translang.phanpy.social",
+      "description": "Space-separated list of Translang instances for translation"
+    },
+    "PHANPY_IMG_ALT_API_URL": {
+      "type": "string",
+      "format": "uri",
+      "description": "API endpoint for self-hosted img-alt-api instance"
+    },
+    "PHANPY_GIPHY_API_KEY": {
+      "type": "string",
+      "minLength": 1,
+      "description": "API key for GIPHY integration"
+    },
+    "PHANPY_DISALLOW_ROBOTS": {
+      "type": ["string", "boolean"],
+      "description": "Set to any value to disallow all web crawlers from indexing the site"
+    }
+  },
+  "additionalProperties": false
+}