Merge origin/main (Tantivy content search) into delta-sync branch

Both sides added a parameter to create_application_services and a
setup step before it: this branch's storage-usage/quota service (for
the instant-upload path) and main's Tantivy content index (for
SearchService). The resolution keeps both — the signature takes both
arguments and the build runs storage usage as step 3c and the content
index as 3d.

https://claude.ai/code/session_01WdNenpnujNR2sc32XVvwfS

src/application/ports/content_index_ports.rs

@@ -0,0 +1,49 @@
+//! Content Index Port - Application layer abstraction for full-text search
+//! over file names and extracted file content.
+//!
+//! The implementation (an embedded Tantivy BM25 index) lives in the
+//! infrastructure layer; `SearchService` only sees this port. The index is a
+//! DERIVED artifact fed asynchronously by a background worker — it never sits
+//! on a request path, and PostgreSQL remains the source of truth (hits are
+//! re-validated and hydrated through SQL before they reach the caller, so a
+//! stale index can only ever produce a dropped candidate, never a leak).
+
+use async_trait::async_trait;
+use uuid::Uuid;
+
+use crate::common::errors::DomainError;
+
+/// One content-index hit: a candidate file id with its BM25 score and an
+/// optional plain-text snippet around the first match.
+///
+/// `file_id` is a CANDIDATE — callers must hydrate it through the metadata
+/// repository (which re-applies user scoping, trash state and the active
+/// search filters) before exposing it.
+#[derive(Debug, Clone)]
+pub struct ContentHitDto {
+    /// File UUID as string (matches `storage.files.id`).
+    pub file_id: String,
+    /// BM25 relevance score (positive, unbounded — normalize per result set).
+    pub score: f32,
+    /// Plain-text fragment around the first matched term, when available.
+    pub snippet: Option<String>,
+}
+
+/// Port for querying the full-text content index.
+///
+/// `#[async_trait]` is used so the trait is dyn-compatible — `SearchService`
+/// holds an `Option<Arc<dyn ContentIndexPort>>` (the feature is toggleable).
+#[async_trait]
+pub trait ContentIndexPort: Send + Sync + 'static {
+    /// Search indexed file names + content for `query`, scoped to `user_id`.
+    ///
+    /// Returns up to `limit` hits sorted by BM25 score descending. Matching is
+    /// tokenized (not substring): exact terms, typo-tolerant fuzzy terms
+    /// (edit distance 1) and prefix expansion on the last query token.
+    async fn search_content(
+        &self,
+        user_id: Uuid,
+        query: &str,
+        limit: usize,
+    ) -> Result<Vec<ContentHitDto>, DomainError>;
+}

src/application/ports/mod.rs

@@ -7,6 +7,7 @@ pub mod calendar_ports;
 pub mod carddav_ports;
 pub mod chunked_upload_ports;
 pub mod compression_ports;
+pub mod content_index_ports;
 pub mod dedup_ports;
 pub mod email_sender;
 pub mod favorites_ports;