Reworks the browse menu/tree interaction into a declarative, contextually
honest model and moves view settings onto a toolbar — the menu is the UI to
the system, so it should be familiar, inviting, and only ever offer what
applies.
New declarative menu model (browse/js/menu-model.js):
- Every action is one descriptor with a TYPE predicate (appliesTo) and a
CAPABILITY predicate (enabled)+tooltip. Row/pane menus are projections over
it; separators are derived from group changes. Designed data-shaped so a
future server-sourced manifest (zddc.zip) can supply/extend it.
- Hybrid visibility: type-inapplicable actions are OMITTED (New folder on a
file, Expand on a file); permission/role/tier-gated actions are SHOWN
DISABLED with a reason — so a lower tier sees what a higher role unlocks.
- Roles are NOT hardcoded: ordinary actions gate on the verbs the server
returns (node.verbs / path_verbs), so any operator-defined role works. Only
the two intrinsically-special tiers are recognised by name — site admin
(is_super_admin) and project/subtree admin (path_is_admin), surfaced as the
"Edit access rules…" item; both come from the existing /.profile/access.
- The headline fix: New folder / New markdown file no longer appear on file
rows (they target a folder or the current dir).
events.js: deletes the ~350-line inline buildTreeRowMenu/buildPaneMenu/
SORT_BY_ITEMS; opens menus via menuModel projections through one openRowMenuFor
/openPaneMenu path shared by right-click, the hover kebab, and the keyboard
menu key (ContextMenu / Shift+F10). Injects action impls via menuModel.configure
to avoid a circular dep. Prefetches the scope /.profile/access (memoised) on
load/rescope/refresh/popstate so menus never fetch at open time.
Discoverability + a11y: a per-row ⋯ kebab (tree.js + new icon-ellipsis sprite,
revealed on hover/selection/focus) opens the same menu; keyboard menu key
supported.
Toolbar: Sort + Show-hidden moved OUT of per-row right-click menus into the
tree-pane toolbar, plus New folder / New file buttons (act on the current dir,
greyed with a reason when create access is lacking). Help copy updated.
Icons: dropped the 3 stray emoji from menu items (consistent, VS Code/Finder
style); only new sprite is the kebab's icon-ellipsis.
Tests: +5 browse specs (file row omits New-folder; folder row shows it; a
read-only server node greys Rename with a "write access" tooltip via a pure
menuModel unit; toolbar Sort/Show-hidden drive state + New buttons present;
kebab and Shift+F10 both open the menu). All 23 browse+conflict+diff green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The persistent #statusBar strip held whatever last-action message
was written ("Loaded N items", "Created folder X", error text, …)
and stuck around indefinitely, overlapping content while adding
little value. Deleted the strip; existing statusInfo/statusError
call sites now thunk through window.zddc.toast (the shared toast
helper every tool already bundles).
- Same function signatures: events.statusInfo /
events.statusError keep working without touching the 70+ call
sites across app.js, download.js, events.js, etc.
- plan-review.js had its own private statusInfo/statusError pair
(duplicated the DOM write); updated to route through
zddc.toast as well.
- statusClear becomes a no-op — toasts fade on their own (5s
info, 8s error via cap-toast) and the toast helper's
single-toast policy guarantees only the latest is visible.
Removed: #statusBar div from template.html, .status-bar / .is-error
/ .is-info / --error / --info rules from base.css and tree.css.
Zero remaining `statusBar` or `status-bar` references in the built
browse.html. Full Playwright suite green (243/0/4).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Major upgrade to the browse tool's UX, plus a few shared modules other
tools can adopt.
User-facing:
- Right-click context menu on tree rows AND empty pane space. Traditional
file-manager grouping (Open / Download / New / Rename-Delete / Copy /
Tree ops / View). Items stay visible but disabled when not applicable
so muscle memory carries. Generic shared/context-menu.js framework
supports normal items, toggles, submenus, separators, danger styling.
- YAML editor for .yaml / .yml / .zddc files (CodeMirror 5 vendored at
shared/vendor/codemirror-yaml.min.*). js-yaml lint on every change
for parse errors. For .zddc cascade files, an additional schema-aware
lint pass flags unknown keys, bad enum values, and wrong types.
- Per-row drag-drop upload using webkitGetAsEntry (folder uploads work
recursively). Per-row drop indicator; doc-level overlay still fires
for blank-space drops at drop_target scopes.
- New folder / New markdown file context-menu items (server mode).
Rename + Delete with native confirm() dialog. File-API helpers
removeNode / renameNode use the existing PUT/POST/DELETE endpoints.
- Hover info card with the row's full metadata (ZDDC fields + filesystem
info + path/URL). Interactive — mouse into it, drag-select text,
Ctrl/Cmd-C or right-click → Copy. 200ms grace before dismiss.
- Autofilter input at the top of the tree pane. Same grammar as
archive's column filters (zddc.filter.parse / matches). Filters
files; folders without matches collapse out. Non-matching folders
force-open visually when descendants match, without mutating the
user's actual expand state.
- Two-line ZDDC label: title-first, tracking/rev/status as monospace
meta below. Icon column anchors to the title line. Chevron is a
Lucide outline `chevron-right` SVG, rotated 90° on `.expanded`.
- File-type Lucide icon sprite (shared/icons.js — 16 outline glyphs,
~5 KB). PDF / Word / Spreadsheet / Slides / Image / Video / Audio /
CAD / Web / Config / Code / Archive get distinct icons; folders
tinted with --primary.
- Header wraps gracefully at narrow viewports (shared/base.css
flex-wrap + title min-width:0 ellipsis). Body becomes flex column
in browse so a wrapping header doesn't break #appMain height.
- Markdown editor opens in WYSIWYG mode by default. YAML front-matter
+ TOC sidebar reworked: flexbox layout (single visible resizer
between FM and TOC), both bodies overflow:auto for X+Y scrollbars.
- `?file=<path>` deep links open browse pre-positioned at a specific
file. Multi-segment paths walk into subdirectories on the way.
Auto-flips Show hidden when a segment is dot/underscore-prefixed.
- Refresh + show-hidden toggle preserve expansion / selection /
preview pinning. Path-keyed snapshot survives a re-fetched listing.
- "Add Local Directory" → "Use Local Directory" across the four tools
that have it (browse, archive, classifier, +transmittal comment).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds a UI checkbox next to the existing Sort dropdown that surfaces
hidden entries when ACL would otherwise allow read. Default off
(matches today's filtered behavior). On toggle, browse re-fetches
the current directory with ?hidden=1 and re-renders.
┌─ browse toolbar ─────────────────────────────────────────────┐
│ Sort: [Name (A→Z) ▾] ☐ Show hidden │
└──────────────────────────────────────────────────────────────┘
Server-side surface:
- internal/fs/tree.go ListDirectory gains an `includeHidden bool`
parameter. The .-prefix filter (previously hard-coded) now also
drops _-prefix entries (matches dispatch's reserved-prefix guard)
and honors the new flag.
- internal/handler/directory.go reads `?hidden=1` from the request
and threads it through.
- cmd/zddc-server/main.go dispatcher relaxes its dot-prefix and
_-prefix guards for GET/HEAD when `?hidden=1` is set, so clicking
a hidden entry's link works. `_app/` (apps cache) stays
unconditionally reserved — those bytes must go through the apps
resolver. Writes to hidden paths stay blocked (the file API has
its own segment check that the flag does NOT relax).
- internal/listing/listing.go: signature parity (the lower-level
helper that's used by tests + non-cascade listing paths).
Security model unchanged: the ACL chain on the parent dir is the only
real gate. Whoever can read the dir can see its contents — toggling
"Show hidden" just stops the client-side filter from masking
.-prefixed and _-prefixed entries. Hidden paths today:
• <dir>/.zddc ACL YAML — already exposed via /.profile/zddc
• <dir>/.converted/<base> cached MD→DOCX/HTML/PDF, same sensitivity as source
• <root>/.zddc.d/tokens/ per-token metadata; filename = sha256(token)
so not bearer-usable. Default root ACL
restricts to admins; matches /.tokens UI.
• <root>/.zddc.d/logs/ access logs; same admins-only audience
• <root>/_app/ cached upstream tool HTML (public)
• <root>/_template/ install.zip scaffolding (public)
None of these contain bearer credentials or secret material that the
existing ACL doesn't already gate. The walls are still the cascade.
A "⤓ Download (zip)" button in the browse toolbar (shown once a
directory is loaded) downloads the directory you're currently
viewing — and everything under it you're allowed to see — as a single
.zip. Navigate into a subfolder first to grab just that subtree.
- Server mode: an <a download> at "<currentPath>?zip=1" — zddc-server
streams the ACL-filtered zip (see the previous commit), nothing held
in the browser.
- Offline (file://) mode: new browse/js/download.js walks the picked
folder with the FS-Access API in two passes — metadata first (so it
can confirm() before loading >~2000 files / ~500 MB into memory),
then bytes — bundles with the already-vendored JSZip, and triggers a
blob download. Hidden entries (".":/"_"-prefixed) are skipped, the
zip's top level is "<folderName>/…" so it unpacks tidily, and the
status bar shows progress.
Wired in browse/js/events.js (button click + show/hide alongside the
refresh button); concatenated into browse/build.sh; ARCHITECTURE.md +
AGENTS.md note the ?zip=1 endpoint and the button.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
User feedback: the Grid toggle button was on every page and showed an
explanatory empty state when classifier wasn't available — adding UI
to explain why UI didn't work. Cleaner approach: drop the button,
make the URL the source of truth, and default grid mode automatically
inside the only context where it's meaningful.
Behavior:
- Inside any incoming/ path (case-insensitive segment match):
→ grid mode by default
- Everywhere else:
→ browse mode
- Explicit overrides via query string:
?view=grid forces grid (only honored where classifier is
available; otherwise falls back to browse)
?view=browse forces browse (always)
UI changes:
- The Browse/Grid pill toggle is gone.
- grid.js drops both empty-state messages; outside an incoming/
path it just does nothing.
- events.js owns resolveViewMode() / applyResolvedViewMode(),
called on initial mount and after every client-side rescope
(dblclick + popstate).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The tree's underlying setSort API was carried forward from the old
table-with-clickable-headers UI but had no widget driving it after
the layout reshape. Adds an explicit dropdown in the toolbar:
Sort: [Name (A→Z) ▾]
[Name (Z→A) ]
[Modified (new→old) ]
[Modified (old→new) ]
[Size (large→small) ]
[Size (small→large) ]
[Type (A→Z) ]
Implementation:
- new tree.setSortExplicit(key, dir) — sets both axes in one call
(the existing tree.setSort toggles direction on repeat-clicks,
which is the right semantics for column-header clicks but wrong
for an explicit dropdown).
- events.js parses the dropdown value as "<key>:<asc|desc>" and
calls setSortExplicit. The dropdown is initialised to reflect
the current sort state on mount.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reshape browse from "tree-as-table with popup preview" into a unified
file-experience tool with three layered behaviors:
Phase A — Two-pane shell
Phase B — Markdown plugin (Toast UI inline)
Phase C — Grid mode (classifier workflow)
Phase D — Deprecation banners on standalone classifier + mdedit
= Phase A: two-pane shell + lightweight preview plugins =
Browse's table view becomes a tree-pane on the left + preview-pane on
the right with a draggable resizer. Click a folder → expand inline.
Click a file → render in the right pane. The previous popup window
becomes an explicit "⤴ Pop out" button in the right-pane header for
users with a second monitor.
Preview rendering reuses shared/preview-lib.js (PDF iframe, image
<img>, TIFF, ZIP listing, text <pre>). Unknown types show a download
link. browse/js/preview.js refactored into renderInline (default) +
renderInPopup (Pop out button); both share the same plugin
dispatch logic.
Filter rows were already removed earlier this session. Sort columns
likewise — the tree is alphabetical by default; the underlying
setSort API still exists for future re-introduction.
= Phase B: markdown plugin =
New browse/js/preview-markdown.js: when a .md or .markdown file is
clicked, the right pane mounts a Toast UI editor (initial-value =
file contents) with a small toolbar containing Save + dirty indicator
+ status text. Save sends PUT through the file API for server-mode
files; non-server sources are read-only for now (deferred to a
follow-up that wires zddc-source.js writes too). Ctrl+S / Cmd+S
inside the editor saves.
Toast UI Editor (~700 KB JS + ~160 KB CSS) was previously bundled
only in mdedit/vendor/. Moved to shared/vendor/ so browse and mdedit
both pull from one location.
= Phase C: grid mode =
View-mode toggle [Browse | Grid] in the toolbar. Grid mode loads the
classifier tool as an iframe scoped to the current directory (server
mode at working/staging/incoming locations) — classifier's full
bulk-rename workflow without leaving browse. v1 implementation; a
future iteration could bundle classifier's modules directly into
browse for tighter integration. Hostile cases (file:// origin, paths
outside working/staging/incoming) show a friendly explanation
instead of a blank iframe.
new browse/js/grid.js handles the activation logic.
= Phase D: deprecation banners =
mdedit and classifier standalones gain a "this tool is being absorbed
into Browse" advisory banner. Both standalones remain fully
functional and continue to ship — they're useful for offline single-
file editing and air-gapped environments. The banner just points
users toward the unified browse experience.
= Files =
+ browse/js/preview-markdown.js (markdown plugin)
+ browse/js/grid.js (grid-mode plugin)
M browse/template.html (two-pane layout, view toggle, banners)
M browse/css/tree.css (two-pane CSS, replaces table styles)
M browse/js/init.js (state additions: selectedId, viewMode)
M browse/js/tree.js (rowHtml: <tr>+<td> → <div>)
M browse/js/preview.js (renderInline / renderInPopup split)
M browse/js/events.js (toggle wiring, resizer, click handlers
adapted from <table> to <div>)
M browse/build.sh (Toast UI vendor + new modules)
R mdedit/vendor/toastui-* → shared/vendor/ (one bundle, two tools)
M mdedit/build.sh (paths)
M mdedit/template.html (deprecation banner)
M classifier/template.html (deprecation banner)
M tests/browse.spec.js (selectors updated for new layout +
new "click file → preview" test)
Bundle sizes after this commit:
browse: ~1020 KB (was ~290 KB; added Toast UI ~700 KB)
classifier: ~1470 KB (unchanged from prior baseline)
mdedit: ~2140 KB (unchanged; vendor location moved but not added)
What's deferred:
- TOC + front-matter pane in browse's markdown plugin (mdedit has
these; browse v1 uses just the editor).
- FS-API writes from browse's markdown plugin (server PUT works).
- Classifier modules bundled directly into browse (v1 uses iframe).
- Sort UI in the new tree (model still supports it; no widget yet).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The two filter rows (📄 file/ext + 📁 folder) didn't really earn their
header real estate. Browse is for navigating directory structure;
ad-hoc filters across a tree of mixed file types and depths weren't
the right affordance, and the visual weight competed with the column
headers and the breadcrumb. Removed entirely:
- template.html: dropped both <tr class="filter-row"> rows in <thead>,
the related "Filter rows" help section, and the empty-state copy
that mentioned the 📄/📁 rows.
- init.js: dropped state.filters (file/folder/ext slots).
- events.js: dropped the .column-filter[data-filter] input wiring.
- tree.js: dropped recomputeVisibility() and the n.visible plumbing
in visibleIds() and updateCount(). Render is now a straight depth-
first walk over expanded subtrees; the count is just total rows.
setFilter is removed from the public API.
- css/tree.css: dropped .filter-row*, .filter-row__icon, and the
browse-local .column-filter rules (.column-filter is also defined
in shared/base.css for tools that still use it; that stays).
No test changes — tests/browse.spec.js never exercised filters.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Six inline style="" attributes in archive, browse, mdedit templates
moved into stylesheets:
- The font-size:1.1rem override on #refreshHeaderBtn (three tools) is
now a single rule in shared/base.css — the refresh ⟳ glyph genuinely
reads smaller than ◐ / ?, so the rule lives next to the existing
shared icon-button block.
- The flex-start justify-content + select-all margin on archive's
Revisions column header become a .th-content--start variant +
.select-all-checkbox class in archive/css/table.css.
- The 450px initial width + 200px min-width on mdedit's #file-nav move
into mdedit/css/base.css; the runtime resizer continues to override
via inline style.width when the user drags.
No visual change — the output is exactly equivalent.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Single-click still expands the folder inline; double-click swaps the
view's root onto the folder. In server mode it loads the folder's URL
(zddc-server returns a fresh browse instance scoped there); in FS-API
mode it re-roots state.rootHandle onto the folder's handle and re-
enumerates. Files and zips are unchanged — files have a single-click
preview, zips have inline JSZip expansion.
Help panel updated to document the new behavior.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Bring every tool's header in line with archive's pattern:
[logo] [title] [version] [Add Local Directory] [⟳] ............... [◐] [?]
------------- header-left --------------- ----- header-right -
Changes per tool:
* browse: rename "Select Directory" → "Add Local Directory"; add the
red-non-stable wrap to the build label (was missing); add a help
panel + bundle shared/help.js.
* classifier: rename selectDirectoryBtn → addDirectoryBtn,
refreshBtn → refreshHeaderBtn for consistency. Update all JS
callers and welcome-screen copy to the new label.
* mdedit: same id rename. Move the previously-in-pane refresh
button into the header. Stop renaming the dir button to
"Directory: <name>" once a folder is loaded — instead use the
shared btn--subtle variant to de-emphasize while keeping the
standard label.
* transmittal: convert non-standard <div class="app-header"> with
spacer/icons containers to <header class="app-header"> with the
canonical header-left/header-right pair. Move the publish split-
button into header-left (Transmittal-specific primary action).
Remove dead .app-header__spacer/__icons/header-icon-btn CSS now
that nothing references those classes.
* landing, form: add help-btn + help-panel + bundle shared/help.js.
Each panel is tool-specific (project picker docs for landing,
schema-driven form docs for form).
Cross-cutting:
* shared/base.css: promote .btn--subtle from browse/css/tree.css
so any tool with an online mode can de-emphasize Add Local
Directory consistently.
Verified all 7 tools in headless Chromium: header structure correct,
build label red on non-stable cuts, help panel opens + closes via
button + Esc.
- Vendor JSZip locally (shared/vendor/jszip.min.js) and bundle into
the browse build instead of CDN-loading. Eliminates the failure
mode where ZIP rows can't expand because the CDN script doesn't
load (CSP, network, etc.). Tool now works fully offline.
- Replace the toolbar filter input + ext multi-select with two
spreadsheet-style auto-filter rows in <thead>:
- 📄 row: file-name filter + extension filter
- 📁 row: folder-name filter
Each input uses shared/zddc-filter syntax (substring/!negate/
^startsWith/$endsWith/regex/| or/space and).
- New visibility model with ancestor-of-match awareness:
- file matches keep their ancestor folders visible (path-to-hit)
- folder match keeps its descendants visible
- filters compose (file ∧ folder ∧ ext) so combinations narrow
Computed model-side; render walks only visible nodes.
- Replace 🏠 emoji breadcrumb-root with an inline outline-stroke SVG
that tints with currentColor.
Bundles Phase 2 polish + the user-requested header/breadcrumb work:
- Breadcrumbs replacing the plain currentPath span. Server mode
renders linkified ancestor segments (each <a> navigates to that
directory; the browser fetches browse.html, the new instance
auto-loads the listing). FS-API mode renders the rootHandle name
as a non-link (no ancestor handles to navigate). Both prefix the
path with a 🏠 root icon. Trailing slash + bold-current segment
match common file-explorer conventions.
- Subdued 'Select Directory' button in server mode. Once browse is
serving a real directory listing, the local-folder switcher is
available but visually quiet (btn--subtle: transparent, muted
color). FS-API mode keeps the primary styling (it's how the user
got there). New btn--subtle CSS class added to browse's tree.css.
A refresh button (⟳) appears next to it in both modes; clicking
it re-fetches the current root listing.
- Header consistency: browse now matches archive's header layout
(refresh + help buttons in addition to theme on the right). Help
is a placeholder for future help dialog wiring.
- File preview popup. Click a file row → opens a popup window with
the file rendered. Plain types (PDF, HTML, image) load in
iframes; TIFF + ZIP listings via shared/preview-lib.js's
renderTiff / renderZipListing helpers; text via <pre>; unknown
types → 'click Download' placeholder. Modifier-click (ctrl/cmd/
shift) and middle-click still open the file in a new tab via the
underlying <a target=_blank>. Single popup window is reused
across multiple file clicks (matches archive's UX).
- ZIP inline expansion. .zip files have a chevron and act like
folders in the tree. First expand fetches the zip bytes
(server URL or FS handle or parent-zip read), parses with JSZip
(auto-loaded from CDN), and synthesizes the entry tree. Nested
directories within the zip lazy-expand on demand by re-walking
the cached entry list at the right path prefix. Click on a
zip-entry file opens the preview popup with bytes read from
JSZip. Recursive expand-all skips zip archives by design — they
can be very large, and explicit click-to-expand is safer.
- Extension multi-select filter. Toolbar now has a <select
multiple> populated with extensions present in the current
view. Filter is OR-of-selected; combined with the name filter
it's AND-of-both. Folders pass through (so expanding a folder
whose name doesn't match the ext filter still shows its file
children that do match).
Three issues from initial v0.0.12 dev/prod testing:
1. Online listings empty.
directory.go was missing Vary: Accept on its responses, so
browser/CDN cached the HTML response (the embedded browse.html)
and served it again when browse's JS later fetched the same URL
with Accept: application/json. JSON parse failed, autoDetect
returned null, empty state showed. Adds Vary: Accept on both
branches and changes browse.html cache-control to no-cache so
deployed updates land immediately.
2. Top-level folder rows tall, shrink as subtree expands.
The .browse-table had flex:1 in a flex column. <table> in flex
doesn't reliably distribute height across rows — with few rows,
each row stretched. Wrap the table in a div with overflow:auto
and drop flex:1 from the table itself.
3. Recursive expand/collapse.
Shift-click (or alt-click) on a folder now expand-all or
collapse-all its subtree. Plain click still toggles just that
folder. Implementation: tree.expandSubtree() walks BFS, loading
each level's children in parallel, re-rendering between levels
so the user sees progress. tree.collapseSubtree() recursively
marks the subtree collapsed (children stay loaded for instant
re-expand).
A new HTML tool — browse — that lists the contents of any directory.
Designed for ZDDC archives but no ZDDC-specific filtering; just a
straight folder browser with expand/collapse, sort, and name filter.
Modes (auto-detected at page load):
- Online: when served by zddc-server at a folder URL, queries
the same URL with Accept: application/json to load the listing
and renders it. Auto-served as the default at any directory
under ZDDC_ROOT without an index.html (replacing the previous
minimal-HTML stub from directory.go).
- Local: 'Select Directory' button uses FileSystemAccessAPI to
pick any folder on disk; works in Chromium-based browsers.
Features (Phase 1 — what's in this commit):
- Tree view with lazy-loaded folders (children fetched on first
expand).
- Sort by name / size / extension / date (column header click).
- Filter by name substring (toolbar input).
- File click opens in a new tab — for server-backed pages,
routes through zddc-server's normal handler so .archive
redirects + apps cascade overrides + ACL all apply.
Phase 2 deferred:
- ZIP files inline expansion (treat archive entries as virtual
children).
- File preview popup (reuse shared/preview-lib.js).
- Extension multi-select filter.
Wiring:
- browse/ added to top-level ./build's per-tool list, embed
block, versions.txt, and the lockstep release commit + tag set.
All seven tools (archive, transmittal, classifier, mdedit,
landing, form, browse) advance together on stable cuts.
- shared/build-lib.sh: browse added to ZDDC_RELEASE_TOOLS and
verify_channel_links's per-tool loop.
- zddc/internal/apps/embed.go: //go:embed browse.html +
EmbeddedBytes("browse") case.
- zddc/internal/apps/availability.go: browse available at every
directory (same as archive).
- zddc/internal/apps/handler.go: MatchAppHTML routes
/<dir>/browse.html → 'browse'.
- zddc/internal/handler/directory.go: when a directory request
arrives with Accept: text/html and no index.html exists,
serve the embedded browse.html bytes (with a JSON-fallback
if the embedded slot is empty during bootstrap).
