feat(search): tag-based page search surface + per-page tags & collections

Add the /search surface (Pages / Chapters / Mangas tabs) backed by
per-user page tags and per-page collections: schema (migration 0023),
backend endpoints for page tags/collections and tagged-page aggregations
(with the OCR text-search param reserved at 501), plus the frontend API
clients, library Page-tags tab, collection page sections, page context
menu / AddTagsSheet, and reader long-press wiring. Includes the
continuous-reader navigation fixes (?page=N handling, chapter-reset
timing, back-button pops history) and tag-normalization hardening
accumulated on the branch.

Bump version 0.60.2 -> 0.62.0.

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

backend/src/domain/collection.rs

@@ -33,6 +33,22 @@ pub struct CollectionSummary {
     pub sample_covers: Vec<String>,
 }
 
+/// Row returned by `GET /collections/:id/pages`. Joins through
+/// `chapters` and `mangas` so the collection detail view can render a
+/// thumbnail + breadcrumb without per-row follow-up fetches.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct CollectionPageItem {
+    pub page_id: Uuid,
+    pub chapter_id: Uuid,
+    pub manga_id: Uuid,
+    pub page_number: i32,
+    pub chapter_number: i32,
+    pub chapter_title: Option<String>,
+    pub manga_title: String,
+    pub storage_key: String,
+    pub added_at: DateTime<Utc>,
+}
+
 #[derive(Debug, Clone, Deserialize)]
 pub struct NewCollection {
     pub name: String,

backend/src/domain/mod.rs

@@ -7,6 +7,7 @@ pub mod collection;
 pub mod genre;
 pub mod manga;
 pub mod page;
+pub mod page_tag;
 pub mod patch;
 pub mod read_progress;
 pub mod session;
@@ -21,10 +22,14 @@ pub use api_token::ApiToken;
 pub use author::{Author, AuthorRef, AuthorWithCount};
 pub use bookmark::{Bookmark, BookmarkSummary};
 pub use chapter::Chapter;
-pub use collection::{Collection, CollectionSummary};
+pub use collection::{Collection, CollectionPageItem, CollectionSummary};
 pub use genre::{Genre, GenreRef};
 pub use manga::{Manga, MangaCard, MangaDetail};
 pub use page::Page;
+pub use page_tag::{
+    NewPageTag, PageTagSummary, TaggedChapterAggregate, TaggedMangaAggregate,
+    TaggedPageItem,
+};
 pub use patch::Patch;
 pub use read_progress::{ReadProgress, ReadProgressForManga, ReadProgressSummary};
 pub use session::Session;

backend/src/domain/page_tag.rs

@@ -0,0 +1,63 @@
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use sqlx::FromRow;
+use uuid::Uuid;
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct NewPageTag {
+    pub tag: String,
+}
+
+/// Returned by `GET /v1/me/page-tags`. Joins through chapters and
+/// mangas so the library Page-tags tab can render the breadcrumb
+/// without follow-up requests.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct TaggedPageItem {
+    pub tag: String,
+    pub page_id: Uuid,
+    pub chapter_id: Uuid,
+    pub manga_id: Uuid,
+    pub page_number: i32,
+    pub chapter_number: i32,
+    pub chapter_title: Option<String>,
+    pub manga_title: String,
+    pub storage_key: String,
+    pub tagged_at: DateTime<Utc>,
+}
+
+/// Distinct-tags histogram row. Used both for autocomplete in the
+/// "Add tag" sheet and for the chip cloud in the library Page-tags
+/// tab.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct PageTagSummary {
+    pub tag: String,
+    pub count: i64,
+}
+
+/// One chapter (with breadcrumb) ranked by how many of its pages the
+/// caller has tagged with a given tag. Returned by the `/search`
+/// page's Chapters tab via `GET /v1/me/page-tags/chapters`.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct TaggedChapterAggregate {
+    pub chapter_id: Uuid,
+    pub manga_id: Uuid,
+    pub manga_title: String,
+    pub chapter_number: i32,
+    pub chapter_title: Option<String>,
+    pub match_count: i64,
+    /// Up to 3 storage keys of matching pages in this chapter,
+    /// page-number ascending. Powers the thumbnail strip in the row.
+    pub sample_storage_keys: Vec<String>,
+}
+
+/// One manga ranked by how many of its pages (across all chapters)
+/// the caller has tagged with a given tag. Returned by the `/search`
+/// page's Mangas tab.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct TaggedMangaAggregate {
+    pub manga_id: Uuid,
+    pub manga_title: String,
+    pub manga_cover_image_path: Option<String>,
+    pub match_count: i64,
+    pub sample_storage_keys: Vec<String>,
+}