feat(v1.1.5): files SDK + files:* triggers

Filesystem-backed blob storage as the fifth concrete trigger kind.

- `files::collection(c).{create,head,get,update,delete,list}` Rhai SDK
  (blob in/out; metadata maps; missing-field throws naming the field).
- `FilesService` trait in picloud-shared; `FsFilesRepo` (atomic
  write: temp→fsync→rename→fsync-dir→DB; single-pass SHA-256;
  checksum-verified reads → Corrupted) + `FilesServiceImpl` in
  manager-core. Metadata in Postgres (0018), bytes on disk under
  PICLOUD_FILES_ROOT with 0o700 shard dirs.
- `files:*` trigger kind via the Layout-E pattern (0019: widen both
  CHECKs + files_trigger_details), TriggerEvent::Files (metadata only,
  no bytes), emit_files fan-out, dispatcher arm, admin endpoint
  POST /triggers/files (reuses validate_trigger_target).
- AppFilesRead/AppFilesWrite capabilities → script:read/script:write
  (seven-scope commitment held). AppPubsubPublish reserved for v1.1.6.
- Admin files API (list + delete) + dashboard Files view per app.

Cross-app isolation keyed on cx.app_id at every layer. ~45 new tests
(service in-memory, fs tempdir, bridge integration). No DB required
for the suite. publish_ephemeral and the orphan sweep stay deferred.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/manager-core/src/outbox_event_emitter.rs

@@ -19,7 +19,8 @@ use std::sync::Arc;
 
 use async_trait::async_trait;
 use picloud_shared::{
-    DocsEventOp, EmitError, KvEventOp, SdkCallCx, ServiceEvent, ServiceEventEmitter, TriggerEvent,
+    DocsEventOp, EmitError, FileMeta, FilesEventOp, KvEventOp, SdkCallCx, ServiceEvent,
+    ServiceEventEmitter, TriggerEvent,
 };
 
 use crate::outbox_repo::{NewOutboxRow, OutboxRepo, OutboxSourceKind};
@@ -43,6 +44,7 @@ impl ServiceEventEmitter for OutboxEventEmitter {
         match event.source {
             "kv" => self.emit_kv(cx, event).await,
             "docs" => self.emit_docs(cx, event).await,
+            "files" => self.emit_files(cx, event).await,
             // Future sources land here. For now, silently drop — the
             // SDK calls `events.emit(...)` unconditionally for forward
             // compat, so swallowing without an error is correct.
@@ -154,4 +156,68 @@ impl OutboxEventEmitter {
         }
         Ok(())
     }
+
+    /// v1.1.5. Fan out a files mutation across matching files triggers.
+    /// The `ServiceEvent.payload` is the file **metadata** (never the
+    /// blob bytes); `old_payload` is the prior metadata (the deleted
+    /// row's metadata on delete). The `TriggerEvent::Files` carries the
+    /// metadata fields explicitly + `prev` for the change-data-capture
+    /// surface.
+    async fn emit_files(&self, cx: &SdkCallCx, event: ServiceEvent) -> Result<(), EmitError> {
+        let Some(op) = FilesEventOp::from_wire(event.op) else {
+            return Ok(());
+        };
+        let Some(collection) = event.collection.clone() else {
+            return Ok(());
+        };
+        // The payload is the FileMeta JSON the FilesServiceImpl emitted.
+        let Some(meta) = event
+            .payload
+            .clone()
+            .and_then(|v| serde_json::from_value::<FileMeta>(v).ok())
+        else {
+            return Ok(());
+        };
+
+        let matches = self
+            .triggers
+            .list_matching_files(cx.app_id, &collection, op)
+            .await
+            .map_err(|e| EmitError::Unavailable(format!("trigger lookup: {e}")))?;
+
+        if matches.is_empty() {
+            return Ok(());
+        }
+
+        let trigger_event = TriggerEvent::Files {
+            op,
+            collection,
+            id: meta.id.to_string(),
+            name: meta.name,
+            content_type: meta.content_type,
+            size: meta.size,
+            checksum: meta.checksum,
+            prev: event.old_payload.clone(),
+        };
+        let payload = serde_json::to_value(&trigger_event)
+            .map_err(|e| EmitError::Rejected(format!("event serialize: {e}")))?;
+
+        for m in matches {
+            self.outbox
+                .insert(NewOutboxRow {
+                    app_id: cx.app_id,
+                    source_kind: OutboxSourceKind::Files,
+                    trigger_id: Some(m.trigger_id),
+                    script_id: Some(m.script_id),
+                    reply_to: None,
+                    payload: payload.clone(),
+                    origin_principal: cx.principal.as_ref().map(|p| p.user_id),
+                    trigger_depth: cx.trigger_depth.saturating_add(1),
+                    root_execution_id: Some(cx.root_execution_id),
+                })
+                .await
+                .map_err(|e| EmitError::Unavailable(format!("outbox insert: {e}")))?;
+        }
+        Ok(())
+    }
 }