feat: retain explorer filters in navigation mode

README.md

@@ -98,7 +98,7 @@ The dock defaults to the right of the editor workspace. Set `config.file_explore
 
 Both view preferences default to `"tree"`: `config.file_picker_view` and `config.file_explorer_view` independently accept `"list"` or `"tree"`. Set the floating preference to `"list"` to retain the old flat picker. Ctrl+t toggles the current focused instance without rescanning. List retains searchable full relative paths. Tree shows folders first, two-cell indentation, and basename-only files. Folder names end in `/` and use cyan text; files use the normal foreground color. Fold-state arrows are omitted. Maximal single-child directory chains share one row, such as `src/client/http/`; a directory containing one file still gets its own row.
 
-Floating Tree opens in explorer **INSERT** mode; a new docked Tree opens in **NORMAL**. Press `i` in NORMAL to filter; the `i` itself is not added to the query. Typing and Backspace filter full relative paths by case-insensitive whitespace tokens. These are explorer-local modes, not changes to the file buffer's mode. Matching nodes appear with their ancestor context, temporarily revealing descendants without clearing saved expansion. Query changes select a direct match, not merely a contextual ancestor. Escape in explorer INSERT clears the temporary filter and restores explorer NORMAL and its previous selection, retaining explorer focus. Escape from explorer NORMAL returns focus to the buffer (or closes floating search). List always accepts query typing immediately.
+Floating Tree opens in explorer **INSERT** mode; a new docked Tree opens in **NORMAL**. Press `i` in NORMAL to resume editing the existing filter; the `i` itself is not added to the query. Typing and Backspace filter full relative paths by case-insensitive whitespace tokens. These are explorer-local modes, not changes to the file buffer's mode. Matching nodes appear with ancestor context, and query changes initially select a direct match. Escape in INSERT changes only to NORMAL: the filter, visible results, highlighted item, and explorer focus remain. NORMAL displays the active filter and navigates that filtered tree. Escape from NORMAL returns focus to the buffer (or closes floating search). List always accepts query typing immediately.
 
 | File-view input | Behavior |
 | --- | --- |
@@ -108,7 +108,8 @@ Floating Tree opens in explorer **INSERT** mode; a new docked Tree opens in **NO
 | h (NORMAL); Ctrl+h/Left | NORMAL collapses/selects parent; INSERT selects its visible parent without changing the filter |
 | Enter | Toggle a folder, or open the selected file using existing buffer deduplication |
 | `i` (explorer NORMAL) | Enter explorer INSERT/filter mode without inserting `i` |
-| Esc | INSERT → explorer NORMAL, retaining focus; NORMAL → buffer focus or floating close |
+| Esc | INSERT → NORMAL with the filter and selection retained; NORMAL → buffer focus or floating close |
+| Ctrl+u | Clear the filter in NORMAL or INSERT without changing mode/focus; preserve the selected path where possible |
 | Tab | Return to editor focus from a dock |
 | Ctrl+w | Close either presentation |
 | Ctrl+r | Rescan while retaining query, surviving expansion, and selection |
@@ -117,6 +118,8 @@ Floating Tree opens in explorer **INSERT** mode; a new docked Tree opens in **NO
 
 Opening a file from a dock leaves it visible and returns focus to the buffer. Space e refocuses it. Choosing a folder during filtering returns to explorer NORMAL and toggles that folder; it never opens a text buffer for a directory. Selections use actual OS-path identities across filtering, view switches, and refresh; a removed or hidden selection falls back to the nearest visible ancestor, then the first row. Query input never edits the underlying buffer; bracketed paste is ignored while file search is focused. Cancellation preserves buffer mode, selections, and pending Insert history. Invalid, binary, unreadable, or disappeared file selections report an error and keep focus without changing the active buffer.
 
+Clearing returns to the full catalog and reveals the selected file's ancestry in NORMAL when needed. With no current result, it uses the last available selection; removed paths fall back to a visible ancestor, then the first row. Clearing an already empty query is harmless. Filtered folders can be collapsed/expanded in NORMAL without losing the query. Temporary filtered collapse overrides survive mode/view changes and refresh of surviving directories; editing or clearing the query resets them so new matches can be revealed. Choosing a directory during filtering transitions to NORMAL and toggles it while retaining the query.
+
 The project root is the working directory captured at startup. Scanning uses the `ignore` crate for nested `.gitignore` rules and negation; parent/global Git ignore rules are disabled. Hidden regular files and directories are included unless ignored, `.git`/`.jj` metadata is always excluded, and symlink files/directories are not followed. Files open using their original OS paths, not sanitized display labels. Root scan failures report an error; descendant/ignore errors retain reachable entries with an explicit incomplete-scan warning. A failed refresh keeps the prior catalog. There is no background watcher: refresh explicitly after external file changes.
 
 ### Command palette