feat(lanes,run,pricing): Changes sidebar editor, staged groups, image drop, auto pricing

- Changes panel at full screen: the whole Files view (finder, expand-all,
  tree) becomes a left sidebar and the Files tab is dropped; a working-copy
  file opens straight into the editor (Save/Cancel live once the text
  differs, Cancel restores it, Whole file toggles back to the diff), and the
  page is height-locked so the editor no longer collapses with no live run.
- Overview splits into Staged Changes / Changes groups in the work range.
- A changed file's whole tree row takes its status tint.
- Drag an image onto the lane terminal: POST /api/run/drop-image saves it
  (png/jpeg/gif/webp, random name, 0600, pruned after a day) and the path
  is pasted into the pane, which is how claude attaches it.
- Claude Opus 5.5 gets its own pricing row (4/20/0.2/5/8, fast 8/40);
  claude-opus-5% had been pricing it as Opus 5.
- server/lib/pricing-sync.js: a model family used in token_usage with no
  row of its own is inserted from LiteLLM's public price list, never
  updated; off with AGENTHUB_PRICING_SYNC=0. repo-links allows exactly
  that one third-party GitHub raw URL.

docs/LANES.md

@@ -575,7 +575,13 @@ says more than any sentence the dashboard could write.
 
 To the right of the lane detail sits a collapsible **Changes** card (its state
 persists per viewer in `localStorage`). Its header holds **one** control, which
-steps **Narrow** (30%) → **Medium** (50/50) → **Full screen** (the console beside it is hidden, never unmounted) → closed (`agenthub.workspace.changesSize`
+steps **Narrow** (30%) → **Medium** (50/50) → **Full screen** (the console beside it is hidden, never unmounted; the page is
+height-locked so the panel fills the viewport even with no live run; the whole
+Files view (finder, expand-all, tree) becomes a left sidebar and the Files tab
+is dropped, and every working-copy file opened there, from the sidebar, Overview or Review, IS
+the editor (Whole file toggles back to its diff; a commit still opens as a diff) — no
+Edit click, **Save**/**Cancel** stay and wake up once the text differs, Cancel
+restores the saved text) → closed (`agenthub.workspace.changesSize`
 alongside `agenthub.workspace.changesOpen`); the collapsed rail reopens it
 narrow. A stored size from an older build that no longer exists (`wide`) falls back to narrow. Reading a diff and watching a console want opposite amounts of room and
 which one is "work" changes several times an hour, so the width is a step, not
@@ -667,7 +673,11 @@ there is nothing it could mean. It is the dashboard's ONLY commit: the git bar
 above it has none, so no click can sweep the rest of the tree in with `add -A`. **Discard** is the one
 irreversible action in the panel: it asks twice in the UI, and the server
 refuses it without `confirm: true` and accepts only paths `git status` is
-already reporting as changed.
+already reporting as changed. In the `work` range the overview splits like VS
+Code's Source Control: **Staged Changes** (what the next commit takes, each row
+offering Unstage) above **Changes** (unstaged and untracked, each offering
+Stage); a partly staged file appears in both. In the tree, a changed file's
+whole row takes its status tint, not only its letter.
 
 Review, single-file, history and browse do **not** poll: re-fetching under the
 reader's scroll position is worse than a slightly stale view, and those are the