feat(picker): New folder button for Create New's custom folder picker

CLAUDE.md

@@ -232,7 +232,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 The terminal provider scans `terminalLinkLine()`, which extends `terminalPathLine()` for URL continuations in indented paragraphs and table cells. List markers, bare numbers, version tokens, whole email addresses, labels ending in `:`, measurements and clock times (`45%`, `12.3ms`, `10:00:00`) and a `name=value` field under a URL ending in `/` never continue a URL; a token with only `-`, `_` or `.` is also refused when it carries a call paren (`client.get()`) or ends a sentence (`Done.`). A URL in the last column of a space-aligned table never takes the next row's first cell: a continuation row must start inside the URL's own cell, so a gap of two or more spaces between its indent and where the URL starts on the row above means it is the next record. `terminalCellWrappedPaths()` follows each table cell independently: a fragment carries on into the next row only when it ends its cell on `/` or `-` (where a wrapper breaks a path; codex's cell wrap never breaks at `_`), the continuation row is blank to the left of the cell (a wrapper wraps every column of a table row together, so a label there such as `Entry` or `│ Log │` is the next record, unless a left column's path continued on that row too; a left column of wrapped prose, as in a `Description | Path` table, fills that row as well, so the path beside it keeps its per-row fragment links, the safe direction), the next row's token passes `pathContinuation()`, and the cell is no wider than the one above. So a directory that is a whole cell value (`/home/u/proj` over `config.yaml`, or `/home/u/proj/app/` over a labelled `main.py`) keeps its folder link and the next row keeps its own file link. With no label to tell them apart, a directory written with its trailing slash over a relative path in the same column (`/home/u/proj/src/` over `lib/util.ts`) still joins, a known trade-off: it reads exactly like a wrap at `/`. Accepted paths displace other links on their cells. Full-width divider rows stop `terminalLogicalLine()` stitching for both links and touch selection. OSC 8 links confirm the real target URI before the shared opener runs.
 
-**Filesystem path picker** (Link Existing "Browse" + the mobile keyboard's `📁 Path` key): lazy one-directory browsing via `GET /api/filesystem/browse`, with `GET /api/filesystem/preview` for the tapped file. Inserts the path **without** Enter, so the prompt is never submitted; the sibling `⌫ All` key clears only the unsent prompt and must never send the agent's `/clear`. ⚠️ This is a **second file-serving surface and inherits neither the attachment confinement nor its ownership scoping**: it allowlists Home, `CASES_DIR`, `/mnt/d` and `CODEMAN_FILE_PICKER_ROOTS`, blocks sensitive trees, and rejects symlink escapes **after** `realpath`. ⚠️ The optional `sessionId` is an ownership boundary that must be `canAccessOwned`-checked by hand (it does not go through `findSessionOrFail`), and in multi-user mode a non-admin gets only their own `userSpacePath` as a root: per-user spaces live INSIDE `homedir()`, so a `Home` root exposes every other user's workspace. Previews go through the same global conversion limiter, and Markdown/TXT/JSON are served as inert `text/plain`. **New folder** (opt-in per caller, `allowNewFolder`; Link Existing has it): `POST /api/filesystem/mkdir` `{ path, name, sessionId? }` creates ONE folder (non-recursive) directly inside a folder the picker may browse, resolved through the same roots, ownership and blocked-tree rules as browse (`403` outside them or in a blocked tree or unwritable, `404` missing parent, `409` exists, `400` a parent that is a file, or a name outside letters, digits, space and `_ - . ~`, containing `..`, starting with a dot or a tilde or over 255 bytes, so every name it accepts is one Link Existing accepts, and `400` a parent that is a cases directory, where a folder is already a case (Add Case > New Case makes one there); `showHidden` is forwarded like browse's); the picker reloads the folder and selects the new one. A picker that browses somewhere this route cannot create in (the container-workdir picker, `fetchListing`) must not set the flag. → [architecture-invariants#filesystem-path-picker](docs/architecture-invariants.md#filesystem-path-picker)
+**Filesystem path picker** (Link Existing "Browse" + the mobile keyboard's `📁 Path` key): lazy one-directory browsing via `GET /api/filesystem/browse`, with `GET /api/filesystem/preview` for the tapped file. Inserts the path **without** Enter, so the prompt is never submitted; the sibling `⌫ All` key clears only the unsent prompt and must never send the agent's `/clear`. ⚠️ This is a **second file-serving surface and inherits neither the attachment confinement nor its ownership scoping**: it allowlists Home, `CASES_DIR`, `/mnt/d` and `CODEMAN_FILE_PICKER_ROOTS`, blocks sensitive trees, and rejects symlink escapes **after** `realpath`. ⚠️ The optional `sessionId` is an ownership boundary that must be `canAccessOwned`-checked by hand (it does not go through `findSessionOrFail`), and in multi-user mode a non-admin gets only their own `userSpacePath` as a root: per-user spaces live INSIDE `homedir()`, so a `Home` root exposes every other user's workspace. Previews go through the same global conversion limiter, and Markdown/TXT/JSON are served as inert `text/plain`. **New folder** (opt-in per caller, `allowNewFolder`; Link Existing and Create New's custom folder have it): `POST /api/filesystem/mkdir` `{ path, name, sessionId? }` creates ONE folder (non-recursive) directly inside a folder the picker may browse, resolved through the same roots, ownership and blocked-tree rules as browse (`403` outside them or in a blocked tree or unwritable, `404` missing parent, `409` exists, `400` a parent that is a file, or a name outside letters, digits, space and `_ - . ~`, containing `..`, starting with a dot or a tilde or over 255 bytes, so every name it accepts is one Link Existing accepts, and `400` a parent that is a cases directory, where a folder is already a case (Add Case > New Case makes one there); `showHidden` is forwarded like browse's); the picker reloads the folder and selects the new one. A picker that browses somewhere this route cannot create in (the container-workdir picker, `fetchListing`) must not set the flag. → [architecture-invariants#filesystem-path-picker](docs/architecture-invariants.md#filesystem-path-picker)
 
 **File Viewer edit mode** (issue #212): the file-preview overlay edits workspace text files in place: `GET .../file-content?edit=1` + `PUT /api/sessions/:id/file-content`, policy in `src/config/file-editing.ts`. This is a **third file surface and the only one that writes file contents** (the path picker's New folder creates folders only): read-path confinement (realpath + workspace + ownership) plus sensitive/blocked/`.git` denies and an extension **allowlist**; writes are `wx`-temp + rename (no `O_CREAT` anywhere = edit-in-place is structural); optimistic concurrency via sha256 `baseHash` → 409. ⚠️ `edit=1` never truncates and the client must never save a plain-preview buffer (the 500-line truncation would silently delete the rest). ⚠️ CRLF/UTF-8 guards: EOL re-applied server-side, non-UTF-8 refused via round-trip compare. → [architecture-invariants#file-viewer-edit-mode](docs/architecture-invariants.md#file-viewer-edit-mode), `docs/file-viewer-edit-plan.md`
 

docs/architecture-invariants.md

@@ -435,7 +435,7 @@ The terminal provider scans `terminalLinkLine()`, which extends `terminalPathLin
 
 ### Filesystem path picker
 
-**Filesystem path picker** (Link Existing "Browse" button + the extended mobile keyboard's `📁 Path` key): a lazy one-directory-at-a-time browser over `GET /api/filesystem/browse`, with `GET /api/filesystem/preview` serving the tapped file. It starts at the active session's working directory (falling back to the Codeman Cases root, then `/mnt/d`, then the first root), hides dot entries, and inserts the chosen path **without** Enter so the prompt is not submitted. The companion `⌫ All` key clears only the current unsent prompt buffer and must never emit the agent's `/clear` command. **New folder** (opt-in per caller, `allowNewFolder`; Link Existing has it): `POST /api/filesystem/mkdir` `{ path, name, sessionId? }` creates ONE folder (non-recursive) directly inside a folder the picker may browse, resolved through the same roots, ownership and blocked-tree rules as browse (`403` outside them or in a blocked tree or unwritable, `404` missing parent, `409` exists, `400` a parent that is a file, or a name outside letters, digits, space and `_ - . ~`, containing `..`, starting with a dot or a tilde or over 255 bytes, so every name it accepts is one Link Existing accepts, and `400` a parent that is a cases directory, where a folder is already a case (Add Case > New Case makes one there); `showHidden` is forwarded like browse's); the picker reloads the folder and selects the new one. A picker that browses somewhere this route cannot create in (the container-workdir picker, `fetchListing`) must not set the flag.
+**Filesystem path picker** (Link Existing "Browse" button + the extended mobile keyboard's `📁 Path` key): a lazy one-directory-at-a-time browser over `GET /api/filesystem/browse`, with `GET /api/filesystem/preview` serving the tapped file. It starts at the active session's working directory (falling back to the Codeman Cases root, then `/mnt/d`, then the first root), hides dot entries, and inserts the chosen path **without** Enter so the prompt is not submitted. The companion `⌫ All` key clears only the current unsent prompt buffer and must never emit the agent's `/clear` command. **New folder** (opt-in per caller, `allowNewFolder`; Link Existing and Create New's custom folder have it): `POST /api/filesystem/mkdir` `{ path, name, sessionId? }` creates ONE folder (non-recursive) directly inside a folder the picker may browse, resolved through the same roots, ownership and blocked-tree rules as browse (`403` outside them or in a blocked tree or unwritable, `404` missing parent, `409` exists, `400` a parent that is a file, or a name outside letters, digits, space and `_ - . ~`, containing `..`, starting with a dot or a tilde or over 255 bytes, so every name it accepts is one Link Existing accepts, and `400` a parent that is a cases directory, where a folder is already a case (Add Case > New Case makes one there); `showHidden` is forwarded like browse's); the picker reloads the folder and selects the new one. A picker that browses somewhere this route cannot create in (the container-workdir picker, `fetchListing`) must not set the flag.
 
 ⚠️ **This is a second file-serving surface, so it carries the same confinement burden as [Attachments](#attachments) and does not inherit it automatically.** Traversal is allowlisted to Home, `CASES_DIR`, `/mnt/d`, or extra roots explicitly configured via `CODEMAN_FILE_PICKER_ROOTS`; sensitive trees are blocked and symlink escapes are rejected after `realpath` resolution rather than before. Without the realpath step a symlink inside an allowed root would walk straight out of it. `preview` reuses the shared conversion cache and the **global** `document-conversion-limiter`, which is what stops N concurrent large-document previews from forking N multi-minute converter processes. Content types are pinned: images and PDF inline, DOCX/PPTX through the converters, and Markdown/TXT/JSON as inert `text/plain` (never `text/html`, which would be stored XSS on our own origin). Size caps are 2MB for text and 50MB for binary/document previews.
 

docs/wiki/Working-With-Files.md

@@ -171,7 +171,7 @@ choice is remembered per device. The picker inserts the path into your prompt
 **without** pressing Enter, so nothing is submitted by accident. Its sibling **⌫ All**
 key clears the unsent prompt, and never sends the agent's `/clear` command.
 
-In **Link Existing**'s picker, **+📁** (New folder) makes a folder inside the folder you
+In the **Link Existing** and **Create New** (custom folder) pickers, **+📁** (New folder) makes a folder inside the folder you
 are viewing and selects it. Names use letters, numbers, spaces and `_ - . ~` (not starting
 with a dot or `~`). The cases folder is refused, since every folder there is already a
 case: use **Add Case → New Case** instead.

src/web/public/session-ui.js

@@ -4051,6 +4051,7 @@ Object.assign(CodemanApp.prototype, {
       title: 'Choose the folder to create the case in',
       initialPath: input.value.trim(),
       directoriesOnly: true,
+      allowNewFolder: true,
       onSelect: (path) => {
         input.value = path;
         this.updateNewCasePathPreview();

test/path-picker-new-folder.test.ts

@@ -166,13 +166,20 @@ describe('PathPicker New folder', () => {
     expect(doc.querySelector('.path-picker-overlay')).not.toBeNull();
   });
 
+  it("is on for Create New's custom folder picker too", () => {
+    const start = sessionUiJs.indexOf('openNewCasePathPicker() {');
+    expect(sessionUiJs.slice(start, sessionUiJs.indexOf('PathPicker.open', start) + 400)).toContain(
+      'allowNewFolder: true'
+    );
+  });
+
   it('is on for Link Existing and off for the other session-ui pickers', () => {
     const block = (name: string) => {
       const start = sessionUiJs.indexOf(`${name}() {`);
       return sessionUiJs.slice(start, sessionUiJs.indexOf('PathPicker.open', start) + 400);
     };
     expect(block('openLinkCasePathPicker')).toContain('allowNewFolder: true');
-    for (const other of ['openDockerWorkspacePathPicker', 'openDockerWorkdirPicker', 'openNewCasePathPicker']) {
+    for (const other of ['openDockerWorkspacePathPicker', 'openDockerWorkdirPicker', 'openCloneCasePathPicker']) {
       expect(block(other), other).not.toContain('allowNewFolder');
     }
   });