wip schema: arrows between containers

Adds the logical diagram of the project (PNG and its editable Excalidraw
source in docs/) and an Architecture section after the introduction,
with a short description of the data flows.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -10,6 +10,22 @@ devices ──514 udp/tcp──▶ logstream (Go) ──HTTP batches──▶ Vi
                               └──── API / UI ◀─────────┘
 ```
 
+## Architecture
+
+![Schéma logique de Logstream](docs/logstream-schema-logique.png)
+
+- **Ingestion**: syslog (UDP/TCP) and Docker container logs both go through `sink()` (reverse DNS
+  on IP hosts), then the `Store` queue, which sends them in batches to VictoriaLogs.
+- **Live view**: `sink()` also publishes each message to the `Hub`, which streams it to the
+  browsers over SSE.
+- **Search**: the HTTP API turns the UI filters into LogsQL queries sent to VictoriaLogs.
+- **State**: tags and source settings live in `/data` (`logstream-data` volume); the logs
+  themselves in the `vlogs-data` volume.
+
+The editable source of the diagram is
+[`docs/logstream-schema-logique.excalidraw`](docs/logstream-schema-logique.excalidraw)
+(open it on [excalidraw.com](https://excalidraw.com)).
+
 ## Getting started
 
 ```bash
@@ -64,6 +80,12 @@ Severity badges `err`/`crit` and `warning` use the colors of the `error` and `wa
 
 Shortcuts: `/` focuses the search box, `Esc` clears it. Clicking a row shows all its fields.
 
+The column headers stay visible while scrolling. Drag the edge of a header (received, message
+time, severity, host, app) to resize the column, double-click it to go back to the automatic
+width; the message takes the remaining space. Widths are remembered by the browser
+(**Settings > Interface > Reset column widths** restores them all). On phones the list keeps its
+two-line layout without columns.
+
 ## Timeline
 
 The timeline above the list shows the volume of logs per interval, counted by **reception

web/app.js

@@ -126,6 +126,11 @@ const I18N = {
     hDivision: (s) => `interval ${s}`, hCapped: 'enlarged',
     hCappedTitle: 'The chosen division would exceed 300 intervals over this range: it has been enlarged.',
     hUnzoom: '× Reset zoom', unitDay: 'd',
+    toTop: 'Back to top',
+    colRcv: 'Received', colMt: 'Message time', colSev: 'Severity', colHost: 'Host', colApp: 'App', colMsg: 'Message',
+    colGrip: 'Drag to resize, double-click for the automatic width',
+    resetCols: 'Reset column widths', colsReset: 'Column widths reset',
+    colsHelp: 'Drag the edge of a column header in the log list to resize it (remembered by this browser).',
   },
   fr: {
     locale: 'fr-FR',
@@ -250,6 +255,11 @@ const I18N = {
     hDivision: (s) => `intervalle ${s}`, hCapped: 'élargi',
     hCappedTitle: 'La division choisie dépasserait 300 intervalles sur cette plage : elle a été élargie.',
     hUnzoom: '× Annuler le zoom', unitDay: 'j',
+    toTop: 'Revenir en haut',
+    colRcv: 'Réception', colMt: 'Heure message', colSev: 'Sévérité', colHost: 'Hôte', colApp: 'App', colMsg: 'Message',
+    colGrip: 'Glisser pour redimensionner, double-clic pour la largeur automatique',
+    resetCols: 'Réinitialiser les colonnes', colsReset: 'Largeurs de colonnes réinitialisées',
+    colsHelp: 'Glissez le bord d\'un en-tête de colonne de la liste pour la redimensionner (mémorisé par ce navigateur).',
   },
 };
 
@@ -762,6 +772,7 @@ function renderList() {
   addFacetValues(state.rows);
   list.innerHTML = state.rows.map((r) => rowHTML(r, false)).join('');
   bindRows(list.firstElementChild, state.rows);
+  $('#table').hidden = !state.rows.length;
   $('#empty').hidden = state.rows.length > 0 || !$('#error').hidden;
 }
 
@@ -778,6 +789,7 @@ function prependRows(rows) {
   list.insertAdjacentHTML('afterbegin', rows.map((r) => rowHTML(r, true)).join(''));
   bindRows(list.firstElementChild, rows);
   state.rows = rows.concat(state.rows);
+  $('#table').hidden = false;
   while (state.rows.length > MAX_ROWS) {
     state.rows.pop();
     list.lastElementChild?.remove();
@@ -858,6 +870,66 @@ list.addEventListener('keydown', (ev) => {
   if (ev.key === 'Enter' && ev.target.classList.contains('row')) ev.target.click();
 });
 
+/* ================= Column widths ================= */
+
+// Resizable columns of the log list: width in px per column, remembered per
+// browser (logstream.cols.<name>); no stored width = automatic default (CSS).
+const COLS = { rcv: [60, 420], mt: [60, 420], sev: [36, 200], host: [50, 600], app: [40, 600] }; // [min, max]
+const clampCol = (k, w) => Math.min(COLS[k][1], Math.max(COLS[k][0], Math.round(w)));
+
+function applyColWidths() {
+  const table = $('#table');
+  for (const k of Object.keys(COLS)) {
+    const w = parseInt(store.get('cols.' + k, ''), 10);
+    if (w > 0) table.style.setProperty('--col-' + k, clampCol(k, w) + 'px');
+    else table.style.removeProperty('--col-' + k);
+  }
+}
+
+$('#listHead').addEventListener('pointerdown', (ev) => {
+  const grip = ev.target.closest('.grip');
+  if (!grip || ev.button !== 0) return;
+  ev.preventDefault();
+  const k = grip.parentElement.dataset.col;
+  const x0 = ev.clientX;
+  const w0 = grip.parentElement.getBoundingClientRect().width;
+  const table = $('#table');
+  grip.setPointerCapture(ev.pointerId);
+  grip.classList.add('active');
+  document.body.classList.add('col-resizing');
+  const move = (e) => table.style.setProperty('--col-' + k, clampCol(k, w0 + e.clientX - x0) + 'px');
+  const end = () => {
+    grip.removeEventListener('pointermove', move);
+    grip.removeEventListener('pointerup', end);
+    grip.removeEventListener('pointercancel', end);
+    grip.classList.remove('active');
+    document.body.classList.remove('col-resizing');
+    const w = parseInt(table.style.getPropertyValue('--col-' + k), 10);
+    if (w > 0 && w !== Math.round(w0)) store.set('cols.' + k, String(w));
+  };
+  grip.addEventListener('pointermove', move);
+  grip.addEventListener('pointerup', end);
+  grip.addEventListener('pointercancel', end);
+});
+// Double-click on a handle: back to the automatic width.
+$('#listHead').addEventListener('dblclick', (ev) => {
+  const grip = ev.target.closest('.grip');
+  if (!grip) return;
+  store.set('cols.' + grip.parentElement.dataset.col, '');
+  applyColWidths();
+});
+$('#resetCols').addEventListener('click', () => {
+  for (const k of Object.keys(COLS)) store.set('cols.' + k, '');
+  applyColWidths();
+  toast(t('colsReset'));
+});
+
+// The header sticks right under the top bar, whose height changes with the layout.
+new ResizeObserver(([e]) => {
+  document.documentElement.style.setProperty('--topbar-h', Math.ceil(e.target.getBoundingClientRect().height) + 'px');
+}).observe($('.topbar'));
+applyColWidths();
+
 /* ================= Timeline (histogram) ================= */
 
 // Settings > Interface > Timeline, remembered per browser; the first value is the default.
@@ -1447,6 +1519,15 @@ $('#newPill').addEventListener('click', () => {
 });
 window.addEventListener('scroll', debounce(() => { if (window.scrollY <= 80) flushPending(); }, 150), { passive: true });
 
+// "Back to top" button, shown once the page has scrolled a little.
+const syncToTop = () => { $('#toTop').hidden = window.scrollY < 400; };
+window.addEventListener('scroll', syncToTop, { passive: true });
+$('#toTop').addEventListener('click', () => {
+  const smooth = !matchMedia('(prefers-reduced-motion: reduce)').matches;
+  window.scrollTo({ top: 0, behavior: smooth ? 'smooth' : 'auto' });
+});
+syncToTop();
+
 $('#live').addEventListener('click', () => {
   state.live = !state.live;
   store.set('live', state.live ? '1' : '0');

web/index.html

@@ -95,7 +95,17 @@
   <div id="error" class="error-banner" hidden></div>
   <button id="newPill" class="pill" type="button" hidden></button>
 
-  <main id="list" class="list"></main>
+  <div id="table" class="table" hidden>
+    <div id="listHead" class="list-head" role="presentation">
+      <span data-col="rcv"><span class="lbl" data-i18n="colRcv">Received</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="mt"><span class="lbl" data-i18n="colMt">Message time</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="sev"><span class="lbl" data-i18n="colSev">Severity</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="host"><span class="lbl" data-i18n="colHost">Host</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="app"><span class="lbl" data-i18n="colApp">App</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="msg"><span class="lbl" data-i18n="colMsg">Message</span></span>
+    </div>
+    <main id="list" class="list"></main>
+  </div>
   <div id="empty" class="empty" hidden>
     <svg viewBox="0 0 24 24" aria-hidden="true"><path d="M4 6h16M4 12h10M4 18h7"/></svg>
     <p><strong data-i18n="emptyTitle">No matching logs.</strong></p>
@@ -105,6 +115,9 @@
   <footer class="status">
     <span id="conn" class="conn"></span>
     <span id="stats" class="muted"></span>
+    <button id="toTop" class="icon-btn to-top" type="button" data-i18n-title="toTop" data-i18n-aria="toTop" hidden>
+      <svg viewBox="0 0 24 24" aria-hidden="true"><path d="M12 19V5M5 12l7-7 7 7"/></svg>
+    </button>
   </footer>
 
   <dialog id="settingsDlg" class="settings" aria-labelledby="settingsTitle">
@@ -248,6 +261,10 @@
               </div>
               <div id="fontPreview" class="list preview-list" aria-hidden="true"></div>
               <p class="muted small" data-i18n="fontHelp"></p>
+              <div class="cols-row">
+                <button id="resetCols" class="btn ghost" type="button" data-i18n="resetCols">Reset column widths</button>
+                <span class="muted small" data-i18n="colsHelp"></span>
+              </div>
             </section>
             <section class="set-section">
               <h3 data-i18n="histoTitle">Timeline</h3>

web/style.css

@@ -296,6 +296,39 @@ body.busy .progress::after {
 .list { margin: 6px 20px 0; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
 .list:empty { display: none; }
 
+/* Columns: received, message time, severity, host, app, message. Widths come from
+   --col-* (set on #table when a column has been resized, see app.js), shared by
+   the header and every row through subgrid so that the columns line up. */
+.table {
+  display: grid;
+  grid-template-columns: var(--col-rcv, max-content) var(--col-mt, max-content) var(--col-sev, 4.6rem)
+    var(--col-host, minmax(5rem, 9rem)) var(--col-app, minmax(4rem, 8rem)) minmax(0, 1fr);
+  column-gap: 12px;
+  margin: 6px 20px 0; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
+  overflow: clip; /* rounded corners without breaking the sticky header (hidden would) */
+}
+.table[hidden] { display: none; }
+.table .list {
+  display: grid; grid-template-columns: subgrid; grid-column: 1 / -1;
+  margin: 0; border: 0; border-radius: 0; background: none; overflow: visible;
+}
+.table .row { grid-template-columns: subgrid; grid-column: 1 / -1; }
+.list-head {
+  display: grid; grid-template-columns: subgrid; grid-column: 1 / -1;
+  position: sticky; top: var(--topbar-h, 0px); z-index: 5;
+  padding: 0 14px 0 11px; border-left: 3px solid transparent;
+  background: var(--panel-2); border-bottom: 1px solid var(--border);
+  font-size: 10.5px; font-weight: 650; letter-spacing: .04em; text-transform: uppercase; color: var(--muted);
+}
+.list-head > span { position: relative; min-width: 0; padding: 4px 0; }
+/* Labels never widen a column (contain: inline-size), they are cut instead */
+.list-head .lbl { display: block; contain: inline-size; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font: inherit; }
+.list-head .grip { position: absolute; top: 0; bottom: 0; right: -9px; width: 6px; z-index: 1; cursor: col-resize; touch-action: none; }
+.list-head .grip::after { content: ""; position: absolute; left: 2px; top: 25%; bottom: 25%; border-left: 1px solid var(--border); }
+.list-head .grip:hover::after, .list-head .grip.active::after { top: 0; bottom: 0; border-left: 2px solid var(--accent); left: 2px; }
+body.col-resizing, body.col-resizing * { cursor: col-resize !important; user-select: none; -webkit-user-select: none; }
+.cols-row { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 12px; margin-top: 12px; }
+
 .row {
   display: grid;
   grid-template-columns: max-content max-content 4.6rem minmax(5rem, 9rem) minmax(4rem, 8rem) 1fr;
@@ -313,7 +346,8 @@ body.busy .progress::after {
 .row.new { animation: flash 1.2s ease-out; }
 @keyframes flash { from { background: var(--accent-soft); } to { background: transparent; } }
 
-.row time { color: var(--muted); white-space: nowrap; font-variant-numeric: tabular-nums; }
+.row > * { min-width: 0; }
+.row time { color: var(--muted); white-space: nowrap; font-variant-numeric: tabular-nums; overflow: hidden; text-overflow: ellipsis; }
 .row time.rcv { color: var(--text); }
 .row time .ms { opacity: .6; }
 .row .host, .row .app { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
@@ -322,7 +356,7 @@ body.busy .progress::after {
 .row .msg { white-space: pre-wrap; word-break: break-word; min-width: 0; }
 
 .sev {
-  justify-self: start;
+  justify-self: start; max-width: 100%; overflow: hidden; text-overflow: ellipsis;
   font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .03em;
   padding: 1px 6px; border-radius: 5px;
   color: var(--sev); background: color-mix(in srgb, var(--sev) 14%, transparent);
@@ -391,6 +425,10 @@ mark.hit { background: var(--hit); color: inherit; border-radius: 3px; padding:
 .conn.ok::before { color: var(--sev-info); }
 .conn.ko::before { color: var(--sev-err); }
 #stats .bad { color: var(--sev-err); }
+/* "Back to top", at the right end of the status bar: never over a log row */
+.to-top { width: 24px; height: 24px; margin: -5px -6px -5px auto; flex: none; } /* no taller bar */
+.to-top svg { width: 16px; height: 16px; }
+.to-top[hidden] { display: none; }
 
 .toast {
   position: fixed; bottom: 48px; left: 50%; transform: translateX(-50%); z-index: 50;
@@ -593,8 +631,12 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
   #count { flex: 1 1 50%; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
   .histo { padding: 0 16px 6px; }
   .h-leg { display: none; }
-  .list, .error-banner { margin-left: 16px; margin-right: 16px; }
-  .row {
+  .list, .error-banner, .table { margin-left: 16px; margin-right: 16px; }
+  /* Phones: no columns, two lines per log (layout below); the widths do not apply */
+  .table { display: block; }
+  .table .list { display: block; margin: 0; }
+  .list-head { display: none; }
+  .row, .table .row {
     grid-template-columns: auto auto 1fr;
     grid-template-areas: "rcv sev host" "msg msg msg";
     gap: 3px 8px; padding: 8px 12px 8px 10px;