feat(dashboard): replace title tooltips with <help-tip> web component

New custom element (src/components/help-tip.js):
- Floating card appears on hover/focus, appended to document.body
  (position:fixed) so it escapes overflow:hidden in the TOC sidebar
- Attributes: label (bold), description (body), doc (optional
  "Learn more →" link)
- Mouse-over-card grace period so the link stays reachable
- Correct viewport clamping (horizontal + prefer-above/fallback-below)

workstreams.md:
- WHI metric abbreviations (DD/BR/SPR/PEP/CDDR) now use <help-tip>
  with full name, one-sentence description, and doc link
- Domain breakdown labels show domain-scoped stats (open count,
  blocked%, runnable%) and a doc link
- Cycle ⚠ icon upgraded to <help-tip> with explanation
- Removed dotted underline; cursor:help comes from the element CSS

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/src/components/help-tip.js

@@ -0,0 +1,167 @@
+// <help-tip label="Full Name" description="One sentence." doc="/path">ABBR</help-tip>
+//
+// A custom element that shows a floating card on hover/focus.
+// Attributes:
+//   label       — bold title line in the card
+//   description — body text
+//   doc         — optional URL; adds a "Learn more →" link
+//
+// The card is appended to document.body (position:fixed) so it escapes
+// any overflow:hidden or clipping ancestors (e.g. the TOC sidebar).
+
+const _STYLE_ID = "helptip-global-style";
+if (!document.getElementById(_STYLE_ID)) {
+  const s = document.createElement("style");
+  s.id = _STYLE_ID;
+  s.textContent = `
+help-tip {
+  cursor: help;
+  display: inline;
+}
+.helptip-card {
+  position: fixed;
+  z-index: 9999;
+  background: var(--theme-background, #fff);
+  border: 1px solid var(--theme-foreground-faint, #ddd);
+  border-radius: 9px;
+  padding: 0.6rem 0.85rem;
+  max-width: 270px;
+  min-width: 130px;
+  box-shadow: 0 6px 22px rgba(0,0,0,0.13), 0 1px 4px rgba(0,0,0,0.07);
+  font-size: 0.78rem;
+  line-height: 1.5;
+  color: var(--theme-foreground, #333);
+  opacity: 0;
+  transition: opacity 0.12s ease;
+  pointer-events: auto;
+}
+.helptip-card.helptip-visible { opacity: 1; }
+.helptip-card-label {
+  font-weight: 700;
+  font-size: 0.8rem;
+  margin-bottom: 0.3rem;
+  color: var(--theme-foreground, #222);
+}
+.helptip-card-desc {
+  color: var(--theme-foreground-muted, #555);
+}
+.helptip-card-link {
+  display: inline-block;
+  margin-top: 0.45rem;
+  font-size: 0.72rem;
+  color: var(--theme-foreground-focus, #3b82f6);
+  text-decoration: none;
+}
+.helptip-card-link:hover { text-decoration: underline; }
+`;
+  document.head.appendChild(s);
+}
+
+class HelpTip extends HTMLElement {
+  #card      = null;
+  #showTimer = null;
+  #hideTimer = null;
+
+  connectedCallback() {
+    this.addEventListener("mouseenter", this.#onEnter);
+    this.addEventListener("mouseleave", this.#onLeave);
+    this.addEventListener("focusin",    this.#onEnter);
+    this.addEventListener("focusout",   this.#onLeave);
+  }
+
+  disconnectedCallback() {
+    clearTimeout(this.#showTimer);
+    clearTimeout(this.#hideTimer);
+    this.#clearCard();
+    this.removeEventListener("mouseenter", this.#onEnter);
+    this.removeEventListener("mouseleave", this.#onLeave);
+    this.removeEventListener("focusin",    this.#onEnter);
+    this.removeEventListener("focusout",   this.#onLeave);
+  }
+
+  #onEnter = () => {
+    clearTimeout(this.#hideTimer);
+    this.#showTimer = setTimeout(() => this.#showCard(), 80);
+  };
+
+  #onLeave = () => {
+    clearTimeout(this.#showTimer);
+    this.#hideTimer = setTimeout(() => this.#clearCard(), 200);
+  };
+
+  #showCard() {
+    if (this.#card) return;
+
+    const label = this.getAttribute("label")       || "";
+    const desc  = this.getAttribute("description") || "";
+    const doc   = this.getAttribute("doc")         || "";
+
+    const card = document.createElement("div");
+    card.className = "helptip-card";
+
+    if (label) {
+      const h = document.createElement("div");
+      h.className  = "helptip-card-label";
+      h.textContent = label;
+      card.appendChild(h);
+    }
+    if (desc) {
+      const d = document.createElement("div");
+      d.className  = "helptip-card-desc";
+      d.textContent = desc;
+      card.appendChild(d);
+    }
+    if (doc) {
+      const a = document.createElement("a");
+      a.className  = "helptip-card-link";
+      a.textContent = "Learn more →";
+      a.href        = doc;
+      card.appendChild(a);
+    }
+
+    // Keep card alive while mouse is over it
+    card.addEventListener("mouseenter", () => clearTimeout(this.#hideTimer));
+    card.addEventListener("mouseleave", this.#onLeave);
+
+    document.body.appendChild(card);
+    this.#card = card;
+
+    this.#position(card);
+    requestAnimationFrame(() => card.classList.add("helptip-visible"));
+  }
+
+  #position(card) {
+    const rect  = this.getBoundingClientRect();
+    const cw    = card.offsetWidth  || 230;
+    const ch    = card.offsetHeight || 80;
+    const gap   = 8;
+    const vw    = window.innerWidth;
+    const vh    = window.innerHeight;
+
+    // Horizontal: align to left of trigger, clamp inside viewport
+    let left = rect.left;
+    if (left + cw + gap > vw) left = vw - cw - gap;
+    if (left < gap)           left = gap;
+
+    // Vertical: prefer above; fall back to below
+    const top = (rect.top - ch - gap >= 0)
+      ? rect.top - ch - gap
+      : Math.min(rect.bottom + gap, vh - ch - gap);
+
+    card.style.left = `${left}px`;
+    card.style.top  = `${top}px`;
+  }
+
+  #clearCard() {
+    if (this.#card) {
+      this.#card.remove();
+      this.#card = null;
+    }
+  }
+}
+
+if (!customElements.get("help-tip")) {
+  customElements.define("help-tip", HelpTip);
+}
+
+export { HelpTip };

dashboard/src/workstreams.md

@@ -134,6 +134,7 @@ const _domainBreakdown = [...new Set(openWs.map(w => _idToDomain[w.id] ?? "unkno
 ```js
 import {injectTocTop} from "./components/toc-sidebar.js";
 import {withDocHelp}   from "./components/doc-overlay.js";
+import                      "./components/help-tip.js";
 
 // ── Live indicator ────────────────────────────────────────────────────────────
 const _liveEl = html`<div class="live-indicator">
@@ -158,11 +159,11 @@ function _warnLevel(name, val) {
 function _warnColor(lv) { return lv === 2 ? "#dc2626" : lv === 1 ? "#d97706" : "var(--theme-foreground-muted, #666)"; }
 
 const _whiMetrics = [
-  {name: "DD",   val: _DD,   fmt: v => v.toFixed(2),        tip: "Dependency Density — average number of dependencies per open workstream; high values indicate a tightly coupled graph that is hard to parallelise."},
+  {name: "DD",   val: _DD,   fmt: v => v.toFixed(2),           label: "Dependency Density",        desc: "Average number of dependencies per open workstream; high values indicate a tightly coupled graph that is hard to parallelise."},
-  {name: "BR",   val: _BR,   fmt: v => (v*100).toFixed(0)+"%", tip: "Blocked Ratio — share of open workstreams currently in a blocked state; directly reduces the work that can proceed right now."},
+  {name: "BR",   val: _BR,   fmt: v => (v*100).toFixed(0)+"%", label: "Blocked Ratio",             desc: "Share of open workstreams currently in a blocked state; directly reduces the work that can proceed right now."},
-  {name: "SPR",  val: _SPR,  fmt: v => (v*100).toFixed(0)+"%", tip: "Single-Point Risk — share of open workstreams that are depended on by others but have no incoming dependencies themselves; losing one stalls everything downstream."},
+  {name: "SPR",  val: _SPR,  fmt: v => (v*100).toFixed(0)+"%", label: "Single-Point Risk",         desc: "Share of workstreams depended on by others but with no incoming dependencies themselves; losing one stalls everything downstream."},
-  {name: "PEP",  val: _PEP,  fmt: v => (v*100).toFixed(0)+"%", tip: "Parallel Execution Potential — share of open workstreams with zero blocking dependencies that could start or continue immediately."},
+  {name: "PEP",  val: _PEP,  fmt: v => (v*100).toFixed(0)+"%", label: "Parallel Execution Potential", desc: "Share of open workstreams with zero blocking dependencies that could start or continue immediately."},
-  {name: "CDDR", val: _CDDR, fmt: v => (v*100).toFixed(0)+"%", tip: "Cross-Domain Dependency Ratio — share of dependency edges that cross domain boundaries; high values mean progress in one domain is gated on another team or project."},
+  {name: "CDDR", val: _CDDR, fmt: v => (v*100).toFixed(0)+"%", label: "Cross-Domain Dependency Ratio", desc: "Share of dependency edges that cross domain boundaries; high values mean progress in one domain is gated on another team or project."},
 ];
 
 const _whiBox = html`<div class="kpi-infobox whi-box">
@@ -179,8 +180,8 @@ const _whiBox = html`<div class="kpi-infobox whi-box">
         ${_whiMetrics.map(m => {
           const lv = _warnLevel(m.name, m.val);
           return html`<div class="whi-metric-row">
-            <span class="whi-metric-name" style="color:${_warnColor(lv)}" title="${m.tip}">${m.name}</span>
+            <help-tip class="whi-metric-name" style="color:${_warnColor(lv)}" label="${m.label}" description="${m.desc}" doc="/docs/workstream-health-index">${m.name}</help-tip>
-            <span class="whi-metric-val"  style="color:${_warnColor(lv)}">${m.fmt(m.val)}</span>
+            <span class="whi-metric-val" style="color:${_warnColor(lv)}">${m.fmt(m.val)}</span>
           </div>`;
         })}
       </div>
@@ -189,9 +190,12 @@ const _whiBox = html`<div class="kpi-infobox whi-box">
           <div class="whi-domain-header">by domain</div>
           ${_domainBreakdown.map(d => html`<div class="whi-domain-row">
             <span class="whi-domain-dot" style="background:${_whiColor(d.whi)}"></span>
-            <span class="whi-domain-name">${d.domain}</span>
+            <help-tip class="whi-domain-name"
+              label="${d.domain.replaceAll('_', ' ')}"
+              description="Domain-scoped WHI (intra-domain edges only). Open: ${d.openCount} · Blocked: ${(d.br*100).toFixed(0)}% · Runnable: ${(d.pep*100).toFixed(0)}%"
+              doc="/docs/workstream-health-index">${d.domain}</help-tip>
             <span class="whi-domain-score" style="color:${_whiColor(d.whi)}">${(d.whi*100).toFixed(0)}%</span>
-            ${d.cpi === 1 ? html`<span style="color:#d97706;font-size:0.7rem" title="cycle detected">⚠</span>` : ""}
+            ${d.cpi === 1 ? html`<help-tip style="color:#d97706;font-size:0.7rem" label="Dependency Cycle" description="A circular dependency exists within this domain — workstreams are waiting on each other and cannot all proceed." doc="/docs/workstream-health-index">⚠</help-tip>` : ""}
           </div>`)}
         </div>` : ""}
     `}
@@ -323,7 +327,7 @@ if (wsWithDeps.length === 0) {
 .whi-cycle-alert { background: #fef2f2; color: #dc2626; border-radius: 4px; padding: 0.2rem 0.45rem; font-size: 0.72rem; font-weight: 600; margin-bottom: 0.4rem; }
 .whi-metrics { border-top: 1px solid var(--theme-foreground-faint, #eee); padding-top: 0.35rem; margin-bottom: 0.35rem; }
 .whi-metric-row { display: flex; justify-content: space-between; padding: 0.16rem 0; }
-.whi-metric-name { font-family: monospace; font-size: 0.72rem; text-decoration: underline dotted; text-underline-offset: 2px; cursor: help; }
+.whi-metric-name { font-family: monospace; font-size: 0.72rem; }
 .whi-metric-val { font-variant-numeric: tabular-nums; font-weight: 600; font-size: 0.78rem; }
 .whi-domains { border-top: 1px solid var(--theme-foreground-faint, #eee); padding-top: 0.35rem; }
 .whi-domain-header { font-size: 0.65rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--theme-foreground-faint, #aaa); margin-bottom: 0.2rem; }