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/lib.rs

@@ -30,6 +30,9 @@ pub mod dispatcher;
 pub mod docs_filter;
 pub mod docs_repo;
 pub mod docs_service;
+pub mod files_api;
+pub mod files_repo;
+pub mod files_service;
 pub mod gc;
 pub mod http_service;
 pub mod kv_repo;
@@ -96,6 +99,9 @@ pub use dead_letters_api::{dead_letters_router, DeadLettersApiError, DeadLetters
 pub use dispatcher::{compute_backoff, Dispatcher, DispatcherError};
 pub use docs_repo::{DocsRepo, DocsRepoError, PostgresDocsRepo};
 pub use docs_service::DocsServiceImpl;
+pub use files_api::{files_admin_router, FilesAdminState};
+pub use files_repo::{FilesConfig, FilesRepo, FilesRepoError, FsFilesRepo};
+pub use files_service::FilesServiceImpl;
 pub use gc::{spawn_abandoned_gc, spawn_dead_letter_gc};
 pub use http_service::{HttpConfig, HttpServiceImpl};
 pub use kv_repo::{KvRepo, KvRepoError, PostgresKvRepo};
@@ -116,8 +122,9 @@ pub use route_repo::{NewRoute, PostgresRouteRepository, RouteRepository};
 pub use sandbox::{CeilingError, SandboxCeiling};
 pub use trigger_config::{BackoffShape, TriggerConfig};
 pub use trigger_repo::{
-    collection_matches, CreateDeadLetterTrigger, CreateDocsTrigger, CreateKvTrigger,
-    DeadLetterTriggerMatch, DocsTriggerMatch, KvTriggerMatch, PostgresTriggerRepo, Trigger,
-    TriggerDetails, TriggerDispatchMode, TriggerKind, TriggerRepo, TriggerRepoError,
+    collection_matches, CreateDeadLetterTrigger, CreateDocsTrigger, CreateFilesTrigger,
+    CreateKvTrigger, DeadLetterTriggerMatch, DocsTriggerMatch, FilesTriggerMatch, KvTriggerMatch,
+    PostgresTriggerRepo, Trigger, TriggerDetails, TriggerDispatchMode, TriggerKind, TriggerRepo,
+    TriggerRepoError,
 };
 pub use triggers_api::{triggers_router, TriggersApiError, TriggersState};