feat(chat): #155 paste image depuis presse-papier dans le composer custom (QA verte)

- frontend: onPaste sur CustomAgentChatView, détection MIME image, chip/preview d'attachment, envoi via le contrat #154 (adapters/agent, ports)

- backend: import d'image par bytes dans le store attachments (commands, chat_attachments app+infra, dto, ports) + tests

crates/application/src/chat_attachments.rs

@@ -30,14 +30,28 @@ pub struct ImportChatAttachmentsInput {
 /// One source attachment import request.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportChatAttachmentItem {
-    /// Local source path supplied by the driving adapter.
-    pub path: String,
+    /// Source payload supplied by the driving adapter.
+    pub source: ImportChatAttachmentSource,
     /// Optional MIME type supplied by the driving adapter.
     pub mime: Option<String>,
     /// Origin kind.
     pub source_kind: ChatAttachmentSourceKind,
 }
 
+/// Source payload for a chat attachment import.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ImportChatAttachmentSource {
+    /// Local source path supplied by the driving adapter.
+    Path(String),
+    /// In-memory bytes supplied by the driving adapter.
+    Bytes {
+        /// Display filename to persist in metadata and storage name.
+        filename: String,
+        /// Raw content bytes.
+        bytes: Vec<u8>,
+    },
+}
+
 /// Output of [`ImportChatAttachments::execute`].
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportChatAttachmentsOutput {
@@ -70,28 +84,44 @@ impl ImportChatAttachments {
     ) -> Result<ImportChatAttachmentsOutput, AppError> {
         let mut imported = Vec::with_capacity(input.attachments.len());
         for item in input.attachments {
-            let filename = filename_from_path(&item.path)?;
+            let filename = filename_from_source(&item.source)?;
             validate_attachment_filename(&filename)?;
             let mime = sanitize_mime(item.mime.as_deref(), &filename)?;
             let id = ChatAttachmentId::new(self.ids.new_uuid().to_string())
                 .map_err(|err| AppError::Invalid(err.to_string()))?;
-            let attachment = self
-                .store
-                .import_from_path(
-                    &input.project.root,
-                    input.project.id,
-                    input.agent_id,
-                    input.session_id,
-                    &LocalPath::new(item.path),
-                    ChatAttachmentImport {
-                        id,
-                        filename,
-                        mime,
-                        source_kind: item.source_kind,
-                        created_at: now(&self.clock),
-                    },
-                )
-                .await?;
+            let import = ChatAttachmentImport {
+                id,
+                filename,
+                mime,
+                source_kind: item.source_kind,
+                created_at: now(&self.clock),
+            };
+            let attachment = match item.source {
+                ImportChatAttachmentSource::Path(path) => {
+                    self.store
+                        .import_from_path(
+                            &input.project.root,
+                            input.project.id,
+                            input.agent_id,
+                            input.session_id,
+                            &LocalPath::new(path),
+                            import,
+                        )
+                        .await?
+                }
+                ImportChatAttachmentSource::Bytes { bytes, .. } => {
+                    self.store
+                        .import_from_bytes(
+                            &input.project.root,
+                            input.project.id,
+                            input.agent_id,
+                            input.session_id,
+                            &bytes,
+                            import,
+                        )
+                        .await?
+                }
+            };
             imported.push(attachment);
         }
         Ok(ImportChatAttachmentsOutput {
@@ -112,6 +142,13 @@ fn filename_from_path(path: &str) -> Result<String, AppError> {
         .ok_or_else(|| AppError::Invalid("invalid attachment filename".to_owned()))
 }
 
+fn filename_from_source(source: &ImportChatAttachmentSource) -> Result<String, AppError> {
+    match source {
+        ImportChatAttachmentSource::Path(path) => filename_from_path(path),
+        ImportChatAttachmentSource::Bytes { filename, .. } => Ok(filename.clone()),
+    }
+}
+
 fn validate_attachment_filename(filename: &str) -> Result<(), AppError> {
     let lowered = filename.to_ascii_lowercase();
     let blocked = [

crates/application/src/lib.rs

@@ -72,8 +72,8 @@ pub use background::{
     SpawnBackgroundCommandOutput,
 };
 pub use chat_attachments::{
-    ImportChatAttachmentItem, ImportChatAttachments, ImportChatAttachmentsInput,
-    ImportChatAttachmentsOutput, CHAT_ATTACHMENT_MAX_BYTES,
+    ImportChatAttachmentItem, ImportChatAttachmentSource, ImportChatAttachments,
+    ImportChatAttachmentsInput, ImportChatAttachmentsOutput, CHAT_ATTACHMENT_MAX_BYTES,
 };
 pub use conversation::{
     ConversationArchiveProvider, ReadConversationPage, ReadConversationPageInput, RecordTurn,