feat(card): add thumbnail, image, author, timestamp, footer icon_url

- Add `thumbnail` and `image` fields to `Card` for small/large embed images
- Add `author` field for branded attribution bars at the top of embeds
- Add `timestamp` field for ISO 8601 timestamps in the embed footer area
- Expand `footer` from a plain string to `CardFooter { text, icon_url }`
- Update `build_embed()` to map all new fields via serenity's builder API
- Fix `EnvGuard` missing `ANTHROPIC_AUTH_TOKEN` and `GITHUB_COPILOT_API_KEY`

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

Author: vsumner

src/config.rs

@@ -60,14 +60,14 @@ mod tests {
 
     impl EnvGuard {
         fn new() -> Self {
-            // NOTE: Keep in sync with provider env vars that affect test behavior
-            const KEYS: [&str; 27] = [
+            const KEYS: &[&str] = &[
                 "SPACEBOT_DIR",
                 "SPACEBOT_DEPLOYMENT",
                 "SPACEBOT_CRON_TIMEZONE",
                 "SPACEBOT_USER_TIMEZONE",
                 "ANTHROPIC_API_KEY",
                 "ANTHROPIC_BASE_URL",
+                "ANTHROPIC_AUTH_TOKEN",
                 "ANTHROPIC_OAUTH_TOKEN",
                 "OPENAI_API_KEY",
                 "OPENROUTER_API_KEY",
@@ -89,14 +89,15 @@ mod tests {
                 "MINIMAX_CN_API_KEY",
                 "MOONSHOT_API_KEY",
                 "ZAI_CODING_PLAN_API_KEY",
+                "GITHUB_COPILOT_API_KEY",
             ];
 
             let vars = KEYS
-                .into_iter()
-                .map(|key| (key, std::env::var(key).ok()))
+                .iter()
+                .map(|&key| (key, std::env::var(key).ok()))
                 .collect::<Vec<_>>();
 
-            for key in KEYS {
+            for &key in KEYS {
                 unsafe {
                     std::env::remove_var(key);
                 }

src/lib.rs

@@ -742,9 +742,20 @@ impl OutboundResponse {
                 }
             }
             if let Some(footer) = &card.footer
-                && !footer.trim().is_empty()
+                && !footer.text.trim().is_empty()
             {
-                lines.push(footer.trim().to_string());
+                lines.push(footer.text.trim().to_string());
+            }
+            if let Some(author) = &card.author
+                && !author.name.trim().is_empty()
+            {
+                lines.push(author.name.trim().to_string());
+            }
+            if let Some(timestamp) = &card.timestamp
+                && !timestamp.trim().is_empty()
+                && chrono::DateTime::parse_from_rfc3339(timestamp.trim()).is_ok()
+            {
+                lines.push(timestamp.trim().to_string());
             }
             if !lines.is_empty() {
                 sections.push(lines.join("\n\n"));
@@ -763,7 +774,15 @@ pub struct Card {
     pub url: Option<String>,
     #[serde(default)]
     pub fields: Vec<CardField>,
-    pub footer: Option<String>,
+    pub footer: Option<CardFooter>,
+    /// Small image in the top-right corner of the embed.
+    pub thumbnail: Option<CardImage>,
+    /// Large image at the bottom of the embed.
+    pub image: Option<CardImage>,
+    /// Author bar at the top of the embed.
+    pub author: Option<CardAuthor>,
+    /// ISO 8601 timestamp displayed in the footer area.
+    pub timestamp: Option<String>,
 }
 
 /// A field within a generic Card.
@@ -775,6 +794,27 @@ pub struct CardField {
     pub inline: bool,
 }
 
+/// Footer for a Card.
+#[derive(Debug, Clone, Serialize, Deserialize, schemars::JsonSchema)]
+pub struct CardFooter {
+    pub text: String,
+    pub icon_url: Option<String>,
+}
+
+/// Image (thumbnail or main image) for a Card.
+#[derive(Debug, Clone, Serialize, Deserialize, schemars::JsonSchema)]
+pub struct CardImage {
+    pub url: String,
+}
+
+/// Author for a Card.
+#[derive(Debug, Clone, Serialize, Deserialize, schemars::JsonSchema)]
+pub struct CardAuthor {
+    pub name: String,
+    pub url: Option<String>,
+    pub icon_url: Option<String>,
+}
+
 /// Container for interactive elements (maps to ActionRows in Discord).
 /// In Discord, an action row can contain either buttons or a single select menu.
 #[derive(Debug, Clone, Serialize, Deserialize, schemars::JsonSchema)]

src/messaging/discord.rs

@@ -10,10 +10,11 @@ use arc_swap::ArcSwap;
 use async_trait::async_trait;
 use serenity::all::{
     ButtonStyle, ChannelId, ChannelType, Context, CreateActionRow, CreateAttachment, CreateButton,
-    CreateEmbed, CreateEmbedFooter, CreateInteractionResponse, CreateInteractionResponseMessage,
-    CreateMessage, CreatePoll, CreatePollAnswer, CreateSelectMenu, CreateSelectMenuKind,
-    CreateSelectMenuOption, CreateThread, EditMessage, EventHandler, GatewayIntents, GetMessages,
-    Http, Interaction, Message, MessageId, ReactionType, Ready, ShardManager, User, UserId,
+    CreateEmbed, CreateEmbedAuthor, CreateEmbedFooter, CreateInteractionResponse,
+    CreateInteractionResponseMessage, CreateMessage, CreatePoll, CreatePollAnswer,
+    CreateSelectMenu, CreateSelectMenuKind, CreateSelectMenuOption, CreateThread, EditMessage,
+    EventHandler, GatewayIntents, GetMessages, Http, Interaction, Message, MessageId, ReactionType,
+    Ready, ShardManager, Timestamp, User, UserId,
 };
 use std::collections::HashMap;
 use std::sync::Arc;
@@ -1038,7 +1039,39 @@ fn build_embed(card: &crate::Card) -> CreateEmbed {
         embed = embed.url(url);
     }
     if let Some(footer) = &card.footer {
-        embed = embed.footer(CreateEmbedFooter::new(footer));
+        let footer_text = footer.text.trim();
+        if !footer_text.is_empty() {
+            let mut footer_builder = CreateEmbedFooter::new(footer_text);
+            if let Some(icon_url) = &footer.icon_url {
+                footer_builder = footer_builder.icon_url(icon_url);
+            }
+            embed = embed.footer(footer_builder);
+        }
+    }
+    if let Some(thumbnail) = &card.thumbnail {
+        embed = embed.thumbnail(&thumbnail.url);
+    }
+    if let Some(image) = &card.image {
+        embed = embed.image(&image.url);
+    }
+    if let Some(author) = &card.author {
+        let author_name = author.name.trim();
+        if !author_name.is_empty() {
+            let mut author_builder = CreateEmbedAuthor::new(author_name);
+            if let Some(url) = &author.url {
+                author_builder = author_builder.url(url);
+            }
+            if let Some(icon_url) = &author.icon_url {
+                author_builder = author_builder.icon_url(icon_url);
+            }
+            embed = embed.author(author_builder);
+        }
+    }
+    if let Some(timestamp) = &card.timestamp {
+        match timestamp.parse::<Timestamp>() {
+            Ok(ts) => embed = embed.timestamp(ts),
+            Err(e) => tracing::warn!(timestamp, %e, "invalid ISO 8601 timestamp in card, skipping"),
+        }
     }
 
     for (i, field) in card.fields.iter().enumerate() {
@@ -1315,10 +1348,7 @@ mod tests {
         let cards = vec![Card {
             title: Some("Status".into()),
             description: Some("All green".into()),
-            color: None,
-            url: None,
-            fields: Vec::new(),
-            footer: None,
+            ..Default::default()
         }];
 
         let parts = prepare_rich_message_parts(String::new(), &cards, &[], None);

src/tools/reply.rs

@@ -285,7 +285,41 @@ impl Tool for ReplyTool {
                                     "required": ["name", "value"]
                                 }
                             },
-                            "footer": { "type": "string" }
+                            "footer": {
+                                "type": "object",
+                                "properties": {
+                                    "text": { "type": "string" },
+                                    "icon_url": { "type": "string", "format": "uri" }
+                                },
+                                "required": ["text"]
+                            },
+                            "thumbnail": {
+                                "type": "object",
+                                "description": "Small image in the top-right corner of the embed.",
+                                "properties": { "url": { "type": "string", "format": "uri" } },
+                                "required": ["url"]
+                            },
+                            "image": {
+                                "type": "object",
+                                "description": "Large image at the bottom of the embed.",
+                                "properties": { "url": { "type": "string", "format": "uri" } },
+                                "required": ["url"]
+                            },
+                            "author": {
+                                "type": "object",
+                                "description": "Author bar at the top of the embed.",
+                                "properties": {
+                                    "name": { "type": "string" },
+                                    "url": { "type": "string", "format": "uri" },
+                                    "icon_url": { "type": "string", "format": "uri" }
+                                },
+                                "required": ["name"]
+                            },
+                            "timestamp": {
+                                "type": "string",
+                                "format": "date-time",
+                                "description": "ISO 8601 timestamp (e.g. 2024-01-01T00:00:00Z) displayed in the footer area."
+                            }
                         }
                     }
                 },