feat: Sprint 16 — session sidebar visual polish

- Action buttons overlay: wrap pin/move/archive/dup/trash in a
  .session-actions container with position:absolute. Titles now use
  full available width. Actions appear on hover with gradient fade
  from the right edge. Overlay auto-hides during inline rename.

- SVG line icons: replace all emoji HTML entities with monochrome
  SVGs that inherit currentColor. Consistent across all platforms.

- Pin indicator: small gold star rendered inline only when pinned.
  Unpinned sessions get full title width (zero space reservation).

- Project border: sessions assigned to a project show a colored
  left border matching the project color, replacing the old
  always-visible blue folder button.

Fixes both BUGS.md items (title truncation + sticky folder button).
Tests: 214 passed, 23 pre-existing failures, 0 regressions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

BUGS.md

@@ -0,0 +1,18 @@
+# Bugs Backlog
+
+This file tracks UI bugs and polish items to address in a future sprint.
+
+## ~~Conversation list title truncation / hover actions~~ — Fixed (Sprint 16)
+
+- **Was:** Action icons reserved ~30px of space even when invisible, truncating titles.
+- **Fix:** Wrapped all action buttons in a `.session-actions` overlay container with `position:absolute`. Titles now use full available width. Actions appear on hover with a gradient fade from the right edge.
+
+## ~~Folder/project assignment interaction feels sticky~~ — Fixed (Sprint 16)
+
+- **Was:** Folder icon stayed permanently visible (blue, 60% opacity) when a session belonged to a project.
+- **Fix:** Replaced `.has-project` persistent button with a colored left border matching the project color. The folder button now only appears in the hover overlay like all other actions.
+
+## Notes
+
+- Both issues resolved in Sprint 16 (Session Sidebar Visual Polish).
+- Icons replaced from inconsistent emoji HTML entities to monochrome SVG line icons.

ROADMAP.md

@@ -3,7 +3,7 @@
 > Goal: Full 1:1 parity with the Hermes CLI experience via a clean dark web UI.
 > Everything you can do from the CLI terminal, you can do from this UI.
 >
-> Last updated: Sprint 15 (April 1, 2026)
+> Last updated: Sprint 15 / v0.17.1 (April 2, 2026)
 > Tests: 237 passing
 > Source: <repo>/
 

SPRINTS.md

@@ -217,54 +217,55 @@ organizational gap vs. Claude's project folders.
 **Hermes CLI parity impact:** Low (CLI has no session organization)
 **Claude parity impact:** Very High (projects are a core Claude concept)
 
-### Candidates for next sprints
+### Candidates for later sprints
-- Workspace reorder (drag-and-drop)
+- Artifacts + code execution (HTML/SVG preview, inline Python execution)
-- View skill linked files
 - Voice input via Whisper
 - Subagent delegation cards (enhanced tool card rendering)
 
 ---
 
-## Sprint 16 -- Artifacts + Code Execution
+## Sprint 16 -- Session Sidebar Visual Polish (COMPLETED)
 
-**Theme:** See outputs, not just text.
+**Theme:** Make the session list feel high-quality and delightful.
 
-**Why now:** Claude's most distinctive feature is the artifact panel --
+**Why now:** The session sidebar had two visible UX bugs: titles truncated
-code runs inline, HTML renders in a sandboxed iframe, SVGs show as images.
+unnecessarily because action icons reserved space even when hidden, and
-This is the largest single capability gap between what we have and what Claude
+the project folder icon felt "sticky" and awkward. Emoji icons rendered
-feels like. It also directly enables the Hermes "code execution cell" feature
+inconsistently across platforms. These were the most common visual complaints.
-(Jupyter-style in-browser execution).
 
-### Track A: Bugs
+### Track A: Bugs (from BUGS.md)
-- Prism.js autoloader makes one CDN request per language encountered. On a
+- **Session title truncation.** Action icons (pin, move, archive, dup, trash)
-  code-heavy session this causes noticeable latency. Bundle the top 10 languages
+  were always in the DOM with `flex-shrink:0`, reserving ~30px even when
-  (Python, JS, bash, JSON, SQL, YAML, TypeScript, CSS, HTML, Rust) locally.
+  invisible. Fix: wrapped all actions in a `.session-actions` overlay
-- Code blocks in long responses sometimes re-highlight on every renderMessages()
+  container with `position:absolute`. Titles now use full available width.
-  call. Debounce highlightCode() with requestAnimationFrame.
+  Actions appear on hover with a gradient fade from the right edge.
+- **Folder button feels sticky.** Replaced `.has-project` persistent blue
+  button with a colored left border matching the project color. The folder
+  button now only appears in the hover overlay like all other actions.
 
 ### Track B: Features
-- **Artifact panel:** When Hermes produces a code block tagged as `html`, `svg`,
+- **SVG action icons.** Replaced all emoji HTML entities (★, 📂, 📦, ⊕, 🗑)
-  or `react`, a "Preview" button appears on that code block. Clicking it opens
+  with monochrome SVG line icons that inherit `currentColor`. Consistent
-  a sandboxed `<iframe>` in the right panel showing the rendered output. The
+  rendering across macOS, Linux, and Windows. Icons: pin (star), folder,
-  preview updates live if Hermes edits the artifact in a follow-up.
+  archive (box), duplicate (overlapping squares), trash (bin with lines).
-- **Code execution cell:** A "Run" button on Python code blocks. Sends the code
+- **Pin indicator.** Small gold filled-star icon rendered inline before the
-  to a new server endpoint (`POST /api/execute`) which runs it in a subprocess
+  title only when the session is actually pinned. Unpinned sessions get
-  with a 30-second timeout and streams stdout/stderr back as SSE. Output appears
+  full title width with zero space reservation.
-  below the code block inline. This is the Jupyter cell experience without
+- **Project border indicator.** Sessions assigned to a project show a
-  needing a kernel.
+  colored left border matching the project color, replacing the old
-- **Mermaid diagram rendering:** Mermaid.js CDN (deferred). Code blocks tagged
+  always-visible blue folder button.
-  as `mermaid` render as flow/sequence/gantt diagrams inline.
+- **Hover overlay polish.** Actions container uses a gradient background
+  that fades from transparent to the sidebar color, creating a smooth
+  emergence effect. Overlay hides automatically during inline rename.
 
-### Track C: Architecture
+### Deferred to Sprint 17
-- Sandbox safety: `/api/execute` runs in a restricted subprocess (no network,
+- Slash commands (basic set with `commands.js` module)
-  limited filesystem via a temp directory). Returns exit code, stdout, stderr,
+- Thinking/reasoning display for extended-thinking models
-  and execution time.
+- Slash command autocomplete popup
-- Artifact state: artifacts are tracked in `S.artifacts = {}` (code block hash
-  -> rendered content). Persisted in session JSON as `artifacts` array.
 
-**Tests:** ~18 new. Total: ~259.
+**Tests:** 0 new (pure CSS/DOM changes). Total: 237.
-**Hermes CLI parity impact:** High (code execution closes the Jupyter gap)
+**Hermes CLI parity impact:** Low
-**Claude parity impact:** Very High (artifacts are Claude's signature feature)
+**Claude parity impact:** Medium (sidebar polish matches Claude's quality bar)
 
 ---
 
@@ -403,7 +404,7 @@ address.
 | Settings persistence | Done (Sprint 12) |
 | Subagent visibility | Sprint 18 |
 | Background task monitor | Sprint 18 |
-| Code execution (Jupyter) | Sprint 16 |
+| Code execution (Jupyter) | Sprint 17+ |
 | Cron completion alerts | Done (Sprint 13) |
 | Virtual scroll (perf) | Deferred |
 
@@ -419,12 +420,12 @@ address.
 | Tool use visibility | Done (v0.11) |
 | Edit/regenerate messages | Done (v0.10) |
 | Session management | Done (v0.6) |
-| Artifacts (HTML/SVG preview) | Sprint 16 |
+| Artifacts (HTML/SVG preview) | Sprint 17+ |
-| Code execution inline | Sprint 16 |
+| Code execution inline | Sprint 17+ |
 | Mermaid diagrams | Done (Sprint 14) |
 | Projects / folders | Done (Sprint 15) |
 | Pinned/starred sessions | Done (Sprint 12) |
-| Reasoning display | Sprint 18 |
+| Reasoning display | Sprint 16 |
 | Voice input | Sprint 17 |
 | TTS playback | Sprint 17 |
 | Notifications | Done (Sprint 13) |
@@ -448,6 +449,6 @@ address.
 
 ---
 
-*Last updated: April 1, 2026*
+*Last updated: April 2, 2026*
-*Current version: v0.17 | 237 tests*
+*Current version: v0.18 | 237 tests*
-*Next sprint: Sprint 16 (Artifacts + Code Execution)*
+*Next sprint: Sprint 17 (Slash Commands + Thinking Display)*

static/sessions.js

@@ -1,3 +1,14 @@
+// ── Session action icons (SVG, monochrome, inherit currentColor) ──
+const ICONS={
+  pin:'<svg width="14" height="14" viewBox="0 0 16 16" fill="currentColor" stroke="none"><polygon points="8,1.5 9.8,5.8 14.5,6.2 11,9.4 12,14 8,11.5 4,14 5,9.4 1.5,6.2 6.2,5.8"/></svg>',
+  unpin:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><polygon points="8,2 9.8,6.2 14.2,6.2 10.7,9.2 12,13.8 8,11 4,13.8 5.3,9.2 1.8,6.2 6.2,6.2"/></svg>',
+  folder:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><path d="M2 4.5h4l1.5 1.5H14v7H2z"/></svg>',
+  archive:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><rect x="1.5" y="2" width="13" height="3" rx="1"/><path d="M2.5 5v8h11V5"/><line x1="6" y1="8.5" x2="10" y2="8.5"/></svg>',
+  unarchive:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><rect x="1.5" y="2" width="13" height="3" rx="1"/><path d="M2.5 5v8h11V5"/><polyline points="6.5,7 8,5.5 9.5,7"/></svg>',
+  dup:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><rect x="4.5" y="4.5" width="8.5" height="8.5" rx="1.5"/><path d="M3 11.5V3h8.5"/></svg>',
+  trash:'<svg width="14" height="14" viewBox="0 0 16 16" fill="none" stroke="currentColor" stroke-width="1.3"><path d="M3.5 4.5h9M6.5 4.5V3h3v1.5M4.5 4.5v8.5h7v-8.5"/><line x1="7" y1="7" x2="7" y2="11"/><line x1="9" y1="7" x2="9" y2="11"/></svg>',
+};
+
 async function newSession(flash){
   MSG_QUEUE.length=0;updateQueueBadge();
   S.toolCalls=[];
@@ -242,11 +253,35 @@ function renderSessionListFromCache(){
       setTimeout(()=>{inp.focus();inp.select();},10);
     };
 
-    const pin=document.createElement('span');
+    // Pin indicator (inline, only when pinned — no space reserved otherwise)
-    pin.className='session-pin'+(s.pinned?' pinned':'');
+    if(s.pinned){
-    pin.innerHTML=s.pinned?'&#9733;':'&#9734;';
+      const pinInd=document.createElement('span');
-    pin.title=s.pinned?'Unpin':'Pin to top';
+      pinInd.className='session-pin-indicator';
-    pin.onclick=async(e)=>{
+      pinInd.innerHTML=ICONS.pin;
+      el.appendChild(pinInd);
+    }
+    // Project indicator: colored left border
+    if(s.project_id){
+      const proj=_allProjects.find(p=>p.project_id===s.project_id);
+      if(proj){
+        el.style.borderLeftColor=proj.color||'var(--blue)';
+        const dot=document.createElement('span');
+        dot.className='session-project-dot';
+        dot.style.background=proj.color||'var(--blue)';
+        dot.title=proj.name;
+        title.appendChild(dot);
+      }
+    }
+    el.appendChild(title);
+    // Action buttons overlay (appears on hover with gradient fade)
+    const actions=document.createElement('div');
+    actions.className='session-actions';
+    // Pin toggle
+    const pinBtn=document.createElement('button');
+    pinBtn.className='act-pin'+(s.pinned?' pinned':'');
+    pinBtn.innerHTML=s.pinned?ICONS.pin:ICONS.unpin;
+    pinBtn.title=s.pinned?'Unpin':'Pin to top';
+    pinBtn.onclick=async(e)=>{
       e.stopPropagation();e.preventDefault();
       const newPinned=!s.pinned;
       try{
@@ -256,8 +291,15 @@ function renderSessionListFromCache(){
         renderSessionList();
       }catch(err){showToast('Pin failed: '+err.message);}
     };
+    actions.appendChild(pinBtn);
+    // Move to project
+    const move=document.createElement('button');
+    move.className='act-move';move.innerHTML=ICONS.folder;move.title='Move to project';
+    move.onclick=async(e)=>{e.stopPropagation();e.preventDefault();_showProjectPicker(s,move);};
+    actions.appendChild(move);
+    // Archive
     const archive=document.createElement('button');
-    archive.className='session-action-btn';archive.innerHTML=s.archived?'&#9993;':'&#128230;';
+    archive.className='act-archive';archive.innerHTML=s.archived?ICONS.unarchive:ICONS.archive;
     archive.title=s.archived?'Unarchive':'Archive';
     archive.onclick=async(e)=>{
       e.stopPropagation();e.preventDefault();
@@ -269,8 +311,10 @@ function renderSessionListFromCache(){
         showToast(s.archived?'Session archived':'Session restored');
       }catch(err){showToast('Archive failed: '+err.message);}
     };
+    actions.appendChild(archive);
+    // Duplicate
     const dup=document.createElement('button');
-    dup.className='session-dup';dup.innerHTML='&#10697;';dup.title='Duplicate';
+    dup.className='act-dup';dup.innerHTML=ICONS.dup;dup.title='Duplicate';
     dup.onclick=async(e)=>{
       e.stopPropagation();e.preventDefault();
       try{
@@ -282,26 +326,13 @@ function renderSessionListFromCache(){
         }
       }catch(err){showToast('Duplicate failed: '+err.message);}
     };
+    actions.appendChild(dup);
+    // Trash
     const trash=document.createElement('button');
-    trash.className='session-trash';trash.innerHTML='&#128465;';trash.title='Delete';
+    trash.className='act-trash';trash.innerHTML=ICONS.trash;trash.title='Delete';
     trash.onclick=async(e)=>{e.stopPropagation();e.preventDefault();await deleteSession(s.session_id);};
-    // Project move button (folder icon)
+    actions.appendChild(trash);
-    const move=document.createElement('button');
+    el.appendChild(actions);
-    move.className='session-action-btn'+(s.project_id?' has-project':'');
-    move.innerHTML='&#128194;';move.title='Move to project';
-    move.onclick=async(e)=>{e.stopPropagation();e.preventDefault();_showProjectPicker(s,move);};
-    // Project dot indicator
-    if(s.project_id){
-      const proj=_allProjects.find(p=>p.project_id===s.project_id);
-      if(proj){
-        const dot=document.createElement('span');
-        dot.className='session-project-dot';
-        dot.style.background=proj.color||'var(--blue)';
-        dot.title=proj.name;
-        title.appendChild(dot);
-      }
-    }
-    el.appendChild(pin);el.appendChild(title);el.appendChild(move);el.appendChild(archive);el.appendChild(dup);el.appendChild(trash);
 
     // Use a click timer to distinguish single-click (navigate) from double-click (rename).
     // This prevents loadSession from firing on the first click of a double-click,
@@ -309,7 +340,7 @@ function renderSessionListFromCache(){
     let _clickTimer=null;
     el.onclick=async(e)=>{
       if(_renamingSid) return; // ignore while any rename is active
-      if([trash,dup,archive,move].some(b=>e.target===b||b.contains(e.target))) return;
+      if(actions.contains(e.target)) return;
       clearTimeout(_clickTimer);
       _clickTimer=setTimeout(async()=>{
         _clickTimer=null;

static/style.css

@@ -20,13 +20,21 @@
   .session-search input::placeholder{color:var(--muted);opacity:.7;}
   /* Inline session title edit */
   .session-title-input{flex:1;background:rgba(20,32,60,.9);border:1px solid rgba(124,185,255,.6);border-radius:6px;color:var(--text);padding:3px 8px;font-size:13px;outline:none;min-width:0;box-shadow:0 0 0 2px rgba(124,185,255,.15);font-family:inherit;}
-  .session-item{padding:8px 10px 8px 8px;border-radius:8px;cursor:pointer;font-size:13px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;transition:background .15s,color .15s,border-color .15s;display:flex;align-items:center;gap:6px;min-width:0;border-left:2px solid transparent;}
+  .session-item{padding:8px 10px 8px 8px;border-radius:8px;cursor:pointer;font-size:13px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;transition:background .15s,color .15s,border-color .15s;display:flex;align-items:center;gap:6px;min-width:0;border-left:2px solid transparent;position:relative;}
   .session-item:hover{background:rgba(255,255,255,0.06);color:var(--text);}
   .session-item.active{background:rgba(124,185,255,0.1);color:var(--blue);border-left:2px solid var(--blue);padding-left:8px;}
   .session-title{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;}
-  .session-trash{flex-shrink:0;opacity:0;font-size:13px;color:var(--muted);background:none;border:none;cursor:pointer;padding:0 2px;line-height:1;transition:opacity .15s,color .15s;}
+  /* ── Session action button overlay ── */
-  .session-item:hover .session-trash{opacity:1;}
+  .session-actions{position:absolute;right:0;top:0;bottom:0;display:flex;align-items:center;gap:2px;padding:0 6px 0 16px;background:linear-gradient(to right,transparent,var(--sidebar) 12px);opacity:0;pointer-events:none;transition:opacity .15s ease;border-radius:0 8px 8px 0;}
-  .session-trash:hover{color:var(--accent)!important;}
+  .session-item:hover .session-actions{opacity:1;pointer-events:auto;}
+  .session-item.active .session-actions{background:linear-gradient(to right,transparent,rgba(16,33,62,.95) 12px);}
+  .session-actions button{background:none;border:none;color:var(--muted);cursor:pointer;padding:2px 3px;line-height:1;transition:color .12s;display:flex;align-items:center;}
+  .session-actions button:hover{color:var(--text);}
+  .session-actions .act-trash:hover{color:var(--accent);}
+  .session-actions .act-pin.pinned{color:#f5c542;}
+  .session-actions .act-pin.pinned:hover{color:#d4a017;}
+  /* Hide overlay during inline rename */
+  .session-item:has(.session-title-input) .session-actions{display:none;}
   @keyframes newflash{0%{background:rgba(124,185,255,0.22);color:var(--blue);}100%{background:transparent;color:var(--muted);}}
   .session-item.new-flash{animation:newflash 1.4s ease-out forwards;}
   .toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:rgba(20,30,50,.95);backdrop-filter:blur(12px);border:1px solid rgba(124,185,255,0.25);color:var(--text);font-size:13px;padding:10px 20px;border-radius:12px;pointer-events:none;opacity:0;transition:opacity .2s,transform .2s;z-index:100;box-shadow:0 4px 20px rgba(0,0,0,.3);letter-spacing:.01em;}
@@ -495,17 +503,9 @@ body.resizing{user-select:none;cursor:col-resize;}
 .gear-btn{font-size:13px;cursor:pointer;transition:color .15s,background .15s;}
 .gear-btn:hover{color:var(--text);background:rgba(255,255,255,.08);}
 
-/* ── Session pin star ── */
+/* ── Session pin indicator (inline, only when pinned) ── */
-.session-pin{font-size:12px;cursor:pointer;opacity:0;transition:opacity .15s;padding:2px 4px;flex-shrink:0;}
+.session-pin-indicator{flex-shrink:0;color:#f5c542;line-height:1;display:flex;align-items:center;}
-.session-item:hover .session-pin,.session-pin.pinned{opacity:1;}
+.session-pin-indicator svg{width:10px;height:10px;}
-.session-pin.pinned{color:#f5c542;}
-
-/* ── Session duplicate button ── */
-.session-dup,.session-action-btn{background:none;border:none;color:var(--muted);font-size:11px;cursor:pointer;opacity:0;transition:opacity .15s;padding:2px 4px;flex-shrink:0;}
-.session-item:hover .session-dup,.session-item:hover .session-action-btn{opacity:1;}
-.session-dup:hover,.session-action-btn:hover{color:var(--text);}
-.session-action-btn.has-project{opacity:.6;color:var(--blue);}
-.session-item:hover .session-action-btn.has-project{opacity:1;}
 
 /* ── Cron alert badge ── */
 .cron-badge{position:absolute;top:2px;right:2px;background:#e53e3e;color:#fff;font-size:9px;font-weight:700;min-width:14px;height:14px;line-height:14px;text-align:center;border-radius:7px;padding:0 3px;}