docs(user): dashboard, browsing, profile rewrites + new podcasts guide; trash stubs

Ground-truthed against the templates this pass:
- dashboard.md: real section kinds (system shelves incl. Continue
  Series, user collections, custom sections via /custom-section
  builder), Customize Dashboard panel semantics (per-library, drag,
  switches, 10-50 items, Save Changes), Refresh, This Week widget,
  per-item Read/Listen and progress-conflict resolve actions. The old
  page listed a wrong shelf set and never mentioned custom sections.
- library-browsing.md: the file was secretly titled 'Saving Custom
  Filters' and covered nothing else. Now the browsing page: All Books
  toolbar (search, Sort, Filters -> drawer hand-off, Save/Load/Clear
  saved filters), book detail as hub, series pages, podcasts split.
- profile-guide.md: field table ground-truthed from profile_form.templ
  (username/email DO remain editable there), audio defaults (speed,
  resume rewind, keep awake), timezone rendering contract, both theme
  doors (7-pick select vs 37-theme Appearance panel), Change Password
  with live checks, Danger Zone/Remove My Account + last-admin rule.
- podcasts.md NEW: the Podcasts page had zero documentation. Subscribing
  (Add Feed -> RSS URL, library, back-catalog download, download order,
  Add & Subscribe), Continue/All Feeds, Download All, player + Play as
  Sequence cross-link.
- Trashed user-areas.md, frontend-guide.md, settings-guide.md: stubs
  whose planned content now exists as real pages (or duplicates
  profile-guide). user-guide.md rewritten as the plain-language front
  door with a go-here-when table; index.md rows updated to match.
- ui-controls.md: 10 new gate-checked entries for every newly cited
  control (Add & Subscribe via templ-entity fragment).

docs/user/library-browsing.md

@@ -1,58 +1,43 @@
-# Saving Custom Filters
+# Browsing your library
 
-The bookshelf (**All Books**) page lets you save custom filter presets for quick access.
+Everything starts from the **All Books** page: every book you can see in the
+current library, as a wall of covers. From there you narrow, sort, and open.
 
-## Bookshelf Toolbar
+## The All Books toolbar
 
-The All Books page has a toolbar with:
+- The **search box** finds titles, authors, and more as you type
+- The **Sort** dropdown orders the wall (title, author, date added, page
+  count, and more)
+- The **Filters** button opens the filter drawer — authors, tags, series,
+  progress, and every other field (the full how-to lives in
+  [Filters — the complete guide](filters/index.md); this page sticks to
+  browsing)
+- **Save**, **Load**, and **Clear** manage your saved filters: capture the
+  current drawer state under a name, re-apply it any time, and delete ones
+  you no longer want. Saved filters are private to your account.
 
-- A **search input** for quick text searches
-- A **sort** dropdown (title, author, date added, page count)
-- A **Filters** button that opens the filter drawer (author, tags, series, and more)
-- **Save**, **Load**, and **Clear** buttons for filter presets
+Saved filters pair naturally with [smart collections](collections.md): a
+filter answers "what matches right now?", a smart collection keeps matching
+forever.
 
-## How to Save a Filter
+## Opening a book
 
-1. Navigate to the **All Books** page
-2. Click **Filters** to open the drawer, set your desired filters, and click **Apply Filters**
-3. Click the **Save** button in the toolbar
-4. Enter a name for your filter (e.g., "My Sci-Fi Books")
-5. Click **Save**
+Click any cover to open the book's detail page — description, files, your
+progress, actions to read or listen, and the places to edit metadata or fix
+what a scan guessed wrong. The detail page is the hub: series links,
+reviews, bookmarks, and the edit modal all live there.
 
-## Loading Saved Filters
+## Series
 
-1. Click the **Load** button to open the **Saved Filters** dropdown
-2. Click a filter's name to apply it
-3. The filter values are applied instantly, without a page reload
+A book's detail page links to its **series page** — every book in that
+series, in order, for the same library. Series are one of the fields the
+filter drawer can match on too.
 
-## Managing Saved Filters
+## Podcasts are separate
 
-**Delete a filter:**
+Podcast feeds and episodes live on the **Podcasts** page, not the book wall —
+see [Podcasts](podcasts.md).
 
-1. Click the **Load** button to open the **Saved Filters** dropdown
-2. Click the trash icon next to the filter you want to remove
-3. Confirm deletion
-
-**Filter Privacy:**
-
-Saved filters are **private to your account**. Other users cannot see or modify your filters.
-
-## Common Use Cases
-
-**Reading by Genre:**
-
-1. Filter by tag: "Science Fiction"
-2. Save as "Sci-Fi Books"
-3. Quickly access all your sci-fi collection anytime
-
-**Author Collections:**
-
-1. Filter by author: "Isaac Asimov"
-2. Save as "Asimov Books"
-3. Switch between different author collections instantly
-
-**Series Tracking:**
-
-1. Filter by series: "Foundation"
-2. Save as "Foundation Series"
-3. Track your progress through a series
+*Finding your way back:* **All Books** is the wall-of-covers page with the
+**Filters** button; the same toolbar pattern is what you'll see on the
+Podcasts page.