docs: update data model, architecture, and API for v1.15.0 (#66)

Author: GraysonCAdams

docs/api.md

@@ -83,11 +83,12 @@ Response: { "clip": { "id", "status": "downloading", "contentType" } }   (201 Cr
 Triggers the download pipeline via the active provider. Requires a download provider to be configured (see Settings). Returns immediately with status `downloading`.
 
 ### POST /api/clips/share
-Authenticated via `?token=` query parameter (iOS Shortcut token). Allows sharing clips without a session cookie.
+Authenticated via `?token=` query parameter (iOS Shortcut token) or session cookie (web view). Allows sharing clips without a session cookie.
 ```
 Request:  { "url": "https://tiktok.com/...", "phone": "+1234567890" }
 Response: { "ok": true, "clipId": "...", "status": "downloading" }   (201 Created)
 ```
+Also accepts `"phones": ["+1234567890"]` (array) for legacy Shortcut backward compatibility. Records legacy share timestamp for upgrade banner tracking.
 
 ### GET /api/clips/[id]
 Returns full clip detail with user context, interaction state, and metadata.

docs/architecture.md

@@ -116,6 +116,7 @@ scrolly/
 │   │   │   ├── InlineError.svelte
 │   │   │   ├── FilterBar.svelte     # Feed filter tabs
 │   │   │   ├── ShortcutGuideSheet.svelte # iOS Shortcut setup guide
+│   │   │   ├── ShortcutUpgradeBanner.svelte # Legacy shortcut upgrade prompt
 │   │   │   └── settings/
 │   │   │       ├── GroupNameEdit.svelte
 │   │   │       ├── InviteLink.svelte
@@ -141,7 +142,8 @@ scrolly/
 │   │   │   ├── sheetOpen.ts        # Global any-sheet-open state (blocks scroll/nav)
 │   │   │   ├── uiHidden.ts         # Feed UI hidden state (synced from active reel)
 │   │   │   ├── homeTap.ts          # Double-tap home to scroll to top
-│   │   │   └── shortcutNudge.ts    # Share shortcut install nudge
+│   │   │   ├── shortcutNudge.ts    # Share shortcut install nudge
+│   │   │   └── shortcutUpgrade.ts  # Shortcut upgrade banner state
 │   │   ├── types.ts                 # Shared TypeScript types (Clip, etc.)
 │   │   ├── push.ts                  # Client-side push subscription helpers
 │   │   ├── feed.ts                  # Feed data loading

docs/data-model.md

@@ -36,6 +36,8 @@ SQLite database via Drizzle ORM. All IDs are UUIDs stored as text. Timestamps ar
 | muted_by_default | integer | Boolean (0/1). Default 1. |
 | feed_sort_order | text | `'oldest'` / `'round-robin'`. Default `'oldest'`. |
 | avatar_path | text | Nullable. Path to uploaded profile picture. |
+| last_legacy_share_at | integer | Nullable. Unix timestamp of last legacy shortcut share. Used for upgrade banner. |
+| used_new_share_flow | integer | Boolean (0/1). Default 0. Tracks if user has adopted new web view share flow. |
 | removed_at | integer | Nullable. Unix timestamp when removed from group. |
 | created_at | integer | Unix timestamp |