Add trust features: history, trash, export, and collection sharing

Implement Notion-like upgrade phase 4: append-only page revisions with restore-as-a-new-version; recoverable bookmark/page/collection deletions whose restores never resurrect public flags or shares; owner-scoped JSON export; and explicit, revocable read-only collection sharing with owner-only mutations and no transitive third-party bookmark leaks. Add migration 009, API/docs, integration coverage, and page/collections/trash UI.

internal/handlers/export.go

@@ -0,0 +1,83 @@
+package handlers
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/andrew/go-computer/internal/db"
+)
+
+// Structured export (trust phase): a single owner-scoped JSON archive that is
+// richer than the per-item Markdown downloads. It deliberately excludes
+// credentials (IMAP config, CardDAV passwords) and includes only data the
+// caller owns or may read through the owner projection.
+func HandleExport(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	uid := user(r)
+	me, e := db.One(ctx, database(r), `SELECT jsonb_build_object('id',u.id,'name',u.name,'email',u.email,'role',u.role,'createdAt',u."createdAt") FROM "User" u WHERE u.id=$1`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	bookmarks, e := db.Many(ctx, database(r), `SELECT `+db.BookmarkOwnerView+` FROM "Bookmark" b WHERE b."ownerId"=$1 ORDER BY b."createdAt",b.id`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	tags, e := db.Many(ctx, database(r), `SELECT to_jsonb(t)||jsonb_build_object('sharedWith',COALESCE((SELECT jsonb_agg(jsonb_build_object('userId',s."userId",'email',u.email,'name',u.name)) FROM "TagShare" s JOIN "User" u ON u.id=s."userId" WHERE s."tagId"=t.id),'[]'::jsonb)) FROM "Tag" t WHERE t."ownerId"=$1 ORDER BY t."createdAt",t.id`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	pages, e := db.Many(ctx, database(r), `SELECT to_jsonb(p)||jsonb_build_object(
+		'bookmarks',COALESCE((SELECT jsonb_agg(to_jsonb(pb)||jsonb_build_object('bookmark',`+db.BookmarkOwnerView+`) ORDER BY pb.position) FROM "PageBookmark" pb JOIN "Bookmark" b ON b.id=pb."bookmarkId" WHERE pb."pageId"=p.id AND b."ownerId"=$1),'[]'::jsonb),
+		'revisions',COALESCE((SELECT jsonb_agg(to_jsonb(r) ORDER BY r.version) FROM "PageRevision" r WHERE r."pageId"=p.id),'[]'::jsonb))
+		FROM "Page" p WHERE p."ownerId"=$1 ORDER BY p."createdAt",p.id`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	contacts, e := db.Many(ctx, database(r), `SELECT to_jsonb(c) FROM "Contact" c WHERE c."userId"=$1 ORDER BY c."displayName",c.id`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	collections, e := db.Many(ctx, database(r), `SELECT to_jsonb(c) FROM "Collection" c WHERE c."ownerId"=$1 ORDER BY c."createdAt",c.id`, uid)
+	if e != nil {
+		respond(w, 0, nil, e)
+		return
+	}
+	exported := make([]object, 0, len(collections))
+	for _, col := range collections {
+		detail, e := collectionDetail(r, database(r), col)
+		if e != nil {
+			respond(w, 0, nil, e)
+			return
+		}
+		cid := str(col, "id")
+		items, e := db.Many(ctx, database(r), `SELECT to_jsonb(ci)||jsonb_build_object('bookmark',`+db.BookmarkOwnerView+`) FROM "CollectionItem" ci JOIN "Bookmark" b ON b.id=ci."bookmarkId" WHERE ci."collectionId"=$1 ORDER BY ci.position,ci.id`, cid)
+		if e != nil {
+			respond(w, 0, nil, e)
+			return
+		}
+		shares, e := db.Many(ctx, database(r), `SELECT jsonb_build_object('userId',s."userId",'email',u.email,'name',u.name,'createdAt',s."createdAt") FROM "CollectionShare" s JOIN "User" u ON u.id=s."userId" WHERE s."collectionId"=$1 ORDER BY s."createdAt"`, cid)
+		if e != nil {
+			respond(w, 0, nil, e)
+			return
+		}
+		detail["items"], detail["sharedWith"] = items, shares
+		exported = append(exported, detail)
+	}
+	w.Header().Set("Content-Disposition", `attachment; filename="computer-export.json"`)
+	respond(w, 200, object{
+		"format":      "computer-export",
+		"version":     1,
+		"exportedAt":  time.Now().UTC(),
+		"user":        me,
+		"bookmarks":   bookmarks,
+		"tags":        tags,
+		"pages":       pages,
+		"collections": exported,
+		"contacts":    contacts,
+	}, nil)
+}