feat(report): nav scrollspy + offset-jump, чат в плавающее окно справа (#958)

Навигация:
- AnalysisSidebarNav подсвечивает активную секцию через IntersectionObserver
  (rootMargin -72px/-60% — активная полоса ниже sticky-шапки) + aria-current.
- Переход по пунктам — абсолютный window.scrollTo с offset 80px вместо
  scrollIntoView: попадает точно даже после async-подгрузки §6 (высоты
  сдвигаются во время smooth-scroll → раньше «не прыгало»).

Чат:
- ChatPanel больше не вмонтирован внизу колонки. Новый ChatDock оборачивает его
  в fixed сворачиваемое окно справа-снизу (лончер «Спросить по участку», Esc / X
  закрывают) — доступен при любом скролле, едет со скролом (position: fixed).
- Хром дока — только close-бар, чтобы не дублировать собственный заголовок
  ChatPanel (без вложенных карточек). ChatPanel не тронут.

frontend/src/app/site-finder/analysis/[cad]/AnalysisPageContent.tsx

@@ -1,10 +1,10 @@
 "use client";
 
-import { useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import Link from "next/link";
 import { useQueryClient } from "@tanstack/react-query";
 
-import { ChatPanel } from "@/components/site-finder/ChatPanel";
+import { ChatDock } from "@/components/site-finder/ChatDock";
 import { GateVerdictBanner } from "@/components/site-finder/GateVerdictBanner";
 import { HorizonSelector } from "@/components/site-finder/HorizonSelector";
 import { Section1ParcelInfo } from "@/components/site-finder/analysis/Section1ParcelInfo";
@@ -222,11 +222,13 @@ export function AnalysisPageContent({ cad }: Props) {
               Seeded из анализа (geom + financial_estimate), считается по
               запросу; result lazy-mounted (Leaflet). */}
           <Section7Concept analysis={analysis} />
-
-          {/* Chat — grounded parcel-chat over the §22 forecast (#958) */}
-          <ChatPanel cadNum={cad} />
         </div>
       </div>
+
+      {/* Chat — grounded parcel-chat over the §22 forecast (#958). Docked
+          right-side floating panel (position: fixed), доступен при любом
+          скролле; mount once, placement in the tree is irrelevant. */}
+      <ChatDock cadNum={cad} />
     </main>
   );
 }
@@ -404,11 +406,75 @@ const NAV_GROUPS: NavGroup[] = [
   },
 ];
 
+// Top-level section anchors in scroll order — observed by the scrollspy.
+// Children (3.x / 6.x) are intentionally NOT observed: their parent stays lit
+// while the user is anywhere inside the section, which reads cleaner.
+const TOP_LEVEL_IDS: string[] = NAV_GROUPS.flatMap((g) =>
+  g.items.map((i) => i.id),
+);
+
+// Sticky chrome offset (header + breadcrumb). The jump lands the section title
+// just below this; matches scrollMarginTop used on the section cards.
+const SCROLL_OFFSET = 80;
+
+// Robust jump: bare scrollIntoView({behavior:"smooth"}) can land short when
+// async content (§6 forecast loads ~20-40s later) shifts heights mid-animation,
+// and it ignores the sticky offset. Compute an absolute target relative to the
+// document and scroll there, accounting for the sticky chrome.
+function scrollToSection(id: string) {
+  const el = document.getElementById(id);
+  if (!el) return;
+  const top = el.getBoundingClientRect().top + window.scrollY - SCROLL_OFFSET;
+  window.scrollTo({ top, behavior: "smooth" });
+}
+
 function AnalysisSidebarNav() {
-  function scrollTo(id: string) {
+  // Scrollspy: highlight whichever top-level section is currently near the top
-    const el = document.getElementById(id);
+  // of the viewport. Default to the first so something is lit before any scroll.
-    if (el) el.scrollIntoView({ behavior: "smooth" });
+  const [activeId, setActiveId] = useState<string>(TOP_LEVEL_IDS[0]);
-  }
+  const observerRef = useRef<IntersectionObserver | null>(null);
+
+  useEffect(() => {
+    // SSR / unsupported-env guard.
+    if (
+      typeof window === "undefined" ||
+      typeof IntersectionObserver === "undefined"
+    ) {
+      return;
+    }
+
+    const targets = TOP_LEVEL_IDS.map((id) =>
+      document.getElementById(id),
+    ).filter((el): el is HTMLElement => el !== null);
+    if (targets.length === 0) return;
+
+    // Track the set of currently-intersecting sections; the active one is the
+    // first (topmost in scroll order) still inside the band. rootMargin pushes
+    // the band's top down past the sticky chrome and shrinks its bottom so the
+    // "active" section is the one near the top of the viewport — not whatever
+    // merely peeks in from below.
+    const visible = new Set<string>();
+
+    const observer = new IntersectionObserver(
+      (entries) => {
+        for (const entry of entries) {
+          if (entry.isIntersecting) visible.add(entry.target.id);
+          else visible.delete(entry.target.id);
+        }
+        const next = TOP_LEVEL_IDS.find((id) => visible.has(id));
+        if (next) setActiveId(next);
+      },
+      { root: null, rootMargin: "-72px 0px -60% 0px", threshold: 0 },
+    );
+
+    targets.forEach((el) => observer.observe(el));
+    observerRef.current = observer;
+
+    return () => {
+      observer.disconnect();
+      observerRef.current = null;
+    };
+  }, []);
 
   return (
     <nav
@@ -436,64 +502,77 @@ function AnalysisSidebarNav() {
           >
             {group.label}
           </div>
-          {group.items.map((item) => (
+          {group.items.map((item) => {
-            <div key={item.id}>
+            const isActive = activeId === item.id;
-              <button
+            return (
-                type="button"
+              <div key={item.id}>
-                onClick={() => scrollTo(item.id)}
-                style={{
-                  display: "block",
-                  width: "100%",
-                  textAlign: "left",
-                  padding: "8px 16px",
-                  background: "none",
-                  border: "none",
-                  cursor: "pointer",
-                  fontSize: 13,
-                  fontWeight: 500,
-                  color: "var(--fg-primary, #111111)",
-                  transition: "background 0.1s",
-                }}
-                onMouseEnter={(e) => {
-                  e.currentTarget.style.background =
-                    "var(--bg-card-alt, #FAFBFC)";
-                }}
-                onMouseLeave={(e) => {
-                  e.currentTarget.style.background = "none";
-                }}
-              >
-                {item.label}
-              </button>
-              {item.children?.map((child) => (
                 <button
-                  key={child.id}
                   type="button"
-                  onClick={() => scrollTo(child.id)}
+                  onClick={() => scrollToSection(item.id)}
+                  aria-current={isActive ? "true" : undefined}
                   style={{
                     display: "block",
                     width: "100%",
                     textAlign: "left",
-                    padding: "6px 16px 6px 28px",
+                    padding: "8px 16px",
-                    background: "none",
+                    background: isActive
+                      ? "var(--accent-soft, #DBEAFE)"
+                      : "none",
                     border: "none",
+                    borderLeft: isActive
+                      ? "3px solid var(--accent, #1D4ED8)"
+                      : "3px solid transparent",
                     cursor: "pointer",
-                    fontSize: 12,
+                    fontSize: 13,
-                    color: "var(--fg-secondary, #5B6066)",
+                    fontWeight: isActive ? 600 : 500,
-                    transition: "background 0.1s",
+                    color: isActive
+                      ? "var(--accent, #1D4ED8)"
+                      : "var(--fg-primary, #111111)",
+                    transition: "background 0.1s, color 0.1s",
                   }}
                   onMouseEnter={(e) => {
-                    e.currentTarget.style.background =
+                    if (!isActive) {
-                      "var(--bg-card-alt, #FAFBFC)";
+                      e.currentTarget.style.background =
+                        "var(--bg-card-alt, #FAFBFC)";
+                    }
                   }}
                   onMouseLeave={(e) => {
-                    e.currentTarget.style.background = "none";
+                    if (!isActive) e.currentTarget.style.background = "none";
                   }}
                 >
-                  {child.label}
+                  {item.label}
                 </button>
-              ))}
+                {item.children?.map((child) => (
-            </div>
+                  <button
-          ))}
+                    key={child.id}
+                    type="button"
+                    onClick={() => scrollToSection(child.id)}
+                    style={{
+                      display: "block",
+                      width: "100%",
+                      textAlign: "left",
+                      padding: "6px 16px 6px 28px",
+                      background: "none",
+                      border: "none",
+                      cursor: "pointer",
+                      fontSize: 12,
+                      color: "var(--fg-secondary, #5B6066)",
+                      transition: "background 0.1s",
+                    }}
+                    onMouseEnter={(e) => {
+                      e.currentTarget.style.background =
+                        "var(--bg-card-alt, #FAFBFC)";
+                    }}
+                    onMouseLeave={(e) => {
+                      e.currentTarget.style.background = "none";
+                    }}
+                  >
+                    {child.label}
+                  </button>
+                ))}
+              </div>
+            );
+          })}
         </div>
       ))}
     </nav>

frontend/src/components/site-finder/ChatDock.tsx

@@ -0,0 +1,155 @@
+"use client";
+
+/**
+ * ChatDock — floating right-docked wrapper around <ChatPanel> for the Site
+ * Finder analysis report (#958 follow-up).
+ *
+ * The chat used to be mounted inline at the bottom of the report; that meant the
+ * user had to scroll all the way down to ask anything. ChatDock keeps it
+ * always reachable: a fixed launcher (bottom-right) opens a fixed popover panel
+ * that stays put while the report scrolls.
+ *
+ * Open/close:
+ *   - launcher click → toggles the panel open
+ *   - close button (X) → closes
+ *   - Esc → closes (keydown listener active only while open, cleaned up)
+ *
+ * Double-card avoidance: <ChatPanel> already renders its own bordered <section>
+ * card with the «Чат по участку» header. So the dock's own chrome is just a thin
+ * header bar carrying the X close button (NO duplicate title) — ChatPanel's own
+ * header provides the title inside the scrollable body. No nested boxes.
+ *
+ * box-shadow is allowed here (floating popover / launcher), unlike in-page cards.
+ */
+
+import { useEffect, useState } from "react";
+import { MessageSquare, X } from "lucide-react";
+
+import { ChatPanel } from "@/components/site-finder/ChatPanel";
+
+// ── Props ─────────────────────────────────────────────────────────────────────
+
+interface Props {
+  cadNum: string;
+}
+
+// ── ChatDock ───────────────────────────────────────────────────────────────────
+
+export function ChatDock({ cadNum }: Props) {
+  const [open, setOpen] = useState(false);
+
+  // Esc closes the panel (listener active only while open).
+  useEffect(() => {
+    if (!open) return;
+    function onKeyDown(e: KeyboardEvent) {
+      if (e.key === "Escape") setOpen(false);
+    }
+    window.addEventListener("keydown", onKeyDown);
+    return () => window.removeEventListener("keydown", onKeyDown);
+  }, [open]);
+
+  // ── Collapsed: floating launcher ─────────────────────────────────────────────
+
+  if (!open) {
+    return (
+      <button
+        type="button"
+        onClick={() => setOpen(true)}
+        aria-label="Открыть чат по участку"
+        aria-expanded={false}
+        style={{
+          position: "fixed",
+          right: 24,
+          bottom: 24,
+          zIndex: 1000,
+          display: "inline-flex",
+          alignItems: "center",
+          gap: 8,
+          padding: "12px 16px",
+          fontSize: 14,
+          fontWeight: 500,
+          color: "var(--fg-on-dark, #E2E8F0)",
+          background: "var(--accent, #1D4ED8)",
+          border: "1px solid transparent",
+          borderRadius: 12,
+          cursor: "pointer",
+          boxShadow: "0 8px 24px rgba(15, 23, 42, 0.18)",
+          whiteSpace: "nowrap",
+        }}
+      >
+        <MessageSquare size={20} strokeWidth={1.5} aria-hidden />
+        Спросить по участку
+      </button>
+    );
+  }
+
+  // ── Expanded: floating popover panel ─────────────────────────────────────────
+
+  return (
+    <div
+      role="dialog"
+      aria-label="Чат по участку"
+      style={{
+        position: "fixed",
+        right: 24,
+        bottom: 24,
+        zIndex: 1000,
+        width: "min(420px, calc(100vw - 32px))",
+        height: "min(640px, calc(100vh - 120px))",
+        display: "flex",
+        flexDirection: "column",
+        overflow: "hidden",
+        background: "var(--bg-card, #FFFFFF)",
+        border: "1px solid var(--border-card, #E6E8EC)",
+        borderRadius: 12,
+        boxShadow: "0 16px 40px rgba(15, 23, 42, 0.24)",
+      }}
+    >
+      {/* Thin header bar — close affordance only. The title lives in ChatPanel's
+          own header below, so there's no duplicate heading / nested card. */}
+      <div
+        style={{
+          display: "flex",
+          justifyContent: "flex-end",
+          alignItems: "center",
+          padding: "8px 12px",
+          borderBottom: "1px solid var(--border-soft, #EEF0F3)",
+          flexShrink: 0,
+        }}
+      >
+        <button
+          type="button"
+          onClick={() => setOpen(false)}
+          aria-label="Закрыть чат"
+          style={{
+            display: "inline-flex",
+            alignItems: "center",
+            justifyContent: "center",
+            width: 32,
+            height: 32,
+            padding: 0,
+            background: "none",
+            border: "none",
+            borderRadius: 8,
+            cursor: "pointer",
+            color: "var(--fg-secondary, #5B6066)",
+            transition: "background 0.1s",
+          }}
+          onMouseEnter={(e) => {
+            e.currentTarget.style.background = "var(--bg-card-alt, #FAFBFC)";
+          }}
+          onMouseLeave={(e) => {
+            e.currentTarget.style.background = "none";
+          }}
+        >
+          <X size={20} strokeWidth={1.5} aria-hidden />
+        </button>
+      </div>
+
+      {/* Scrollable body — ChatPanel renders normally (its own card + header). */}
+      <div style={{ flex: 1, overflowY: "auto" }}>
+        <ChatPanel cadNum={cadNum} />
+      </div>
+    </div>
+  );
+}