Pivot to text-first column-stack workspace + merge-with-review across AI artifacts

Workspace
- Pivot from "set of open panes" to a Finder-style miller column stack:
  TopBar / LeftSidebar / [section → entity → entity ...] / pinned text editor.
  openPanesStore is now an ordered Column[] with pushFrom / closeFrom /
  setStack; only one top-level section is rooted at a time.
- New entity column panes: Term, Block, Association, Constraint,
  Requirement, Finding. Click-through navigation truncates deeper
  columns automatically.
- LeftSidebar surfaces a pending-count chip per section (single-glance
  navigation cue) and spins its analyze ↻ via SVG Spinner whenever the
  LLM is working — including server-initiated runs caught by the runs
  poll, not just user-triggered ones.

Analyze pipeline + persistence
- Unified `concepts` pass (taxonomy + glossary in one LLM call) replaces
  the two-pass setup. Server still accepts ?section=taxonomy|glossary
  and normalizes them for back-compat.
- model / requirements / detection (assumptions, risks, inconsistencies)
  + cross-layer validation rules (X1–X4: stale term link, unlinked
  formalism, undefined linked term, prose-only term).
- Persistence: NarrativeDocument, ModelSnapshot, ChangelogEntry,
  TaxonomyTerm, RequirementEntry, Finding, AnalysisRun. Re-runs MERGE
  instead of replace: gentle update on existing items, suggested on new,
  deprecated on missing — same idiom for every artifact kind. User pins
  preserve "kept" decisions across re-analyses.
- Migrations: pivot_text_first, add_requirement_linked_term,
  term_review_state, review_state_for_reqs_and_findings,
  add_term_definition_pinned.

Concept ↔ ontology integration
- linkedTermId on Block / Association / Constraint / Requirement.
  PromoteToolbar lets the user formalize a concept inline: + Block /
  + Association / + Constraint / + Requirement, all routed through
  applyOps so undo/redo and SSE work for free.
- decideElement op for in-canvas keep/discard on review-pending model
  elements.

User-authored definitions
- TermColumn definition is click-to-edit. Save (Cmd-Enter / blur),
  Cancel (Esc), Reset to AI suggestion when pinned.
- definitionPinned flag on TaxonomyTerm: future Analyze runs leave the
  user's text alone. setTermDefinition repo function + POST
  /api/projects/[id]/terms/[termId]/definition endpoint.
- mergeTaxonomySuggestion + applyGlossaryDefinitions both pin-aware.

UX/UI
- StatusChip: single component for all state idioms (suggested,
  deprecated, accepted, dismissed, resolved, severity, validation code,
  confidence, warn). Replaces 5+ ad-hoc badge classes.
- PaneControls (PaneViewTabs + PaneFilterChip): separates view-mode
  toggles from filter chips so toggling Pending no longer flips you off
  the current view.
- PaneEmpty: unified empty-state with title + hint + action.
- PaneDrawer: collapsible groups for Pending / Discarded review; cards
  group as Kept (top) → Pending (bottom drawer) → Discarded (Findings
  only, hidden when empty). Restore action recovers dismissed/resolved
  findings.
- ConceptCard unifies Tree and A–Z views in Concepts; only Tree parents
  carry the chevron (no empty placeholder offset).
- Type + spacing tokens (--text-xs..xl, --space-1..6, --lh-tight/ui/
  prose, --radius-*) replace every ad-hoc value.
- Buttons standardized to body sans 500 (was a mishmash of mono / display).
- Card shells unified across Concepts / Requirements / Findings.

Cleanup
- Removed: LeftRail, FindingsPanel, IssuesPanel, SocratesDock,
  ProposalCard, SlashMenu, SlashExtension, slashSuggestion,
  CanvasHeader, TaxonomyPane, GlossaryPane, TermDetail (popover; now
  TermColumn).
- Section ids in openPanesStore: dropped taxonomy/glossary, added
  concepts. localStorage migration runs on hydrate.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/components/editor/PaneDrawer.tsx

@@ -0,0 +1,75 @@
+// PaneDrawer — collapsible group inside a list pane. Used to group rows by
+// review state without losing screen real estate when a group is empty or
+// the user doesn't want to see it.
+//
+// Stack layout: Kept list (always-on, fills) → [Pending drawer] → [Discarded
+// drawer]. Drawers always render their header (so the count is visible at a
+// glance); their body collapses on toggle.
+//
+// Tone is one of:
+//   "default" — neutral, used for kept-only views
+//   "pending" — accent strip + count chip in accent
+//   "muted"   — dim styling, used for the Discarded drawer
+//
+// The drawer is non-sticky on purpose: the user can scroll past kept items
+// to reach pending, and the kept count never gets crushed by an over-tall
+// drawer. CSS lives in styles/base.css under .pane-drawer.
+
+"use client";
+
+import { useState, type ReactNode } from "react";
+
+interface PaneDrawerProps {
+  title: string;
+  /** Optional count rendered as a pip in the header. */
+  count?: number;
+  /** Visual tone. */
+  tone?: "default" | "pending" | "muted";
+  /** Initial expanded state. */
+  defaultOpen?: boolean;
+  /** When the drawer would be empty AND `hideWhenEmpty` is true, the entire
+   *  drawer (header included) is omitted. Useful for the Discarded drawer
+   *  where 0 items means "nothing dismissed yet, don't even show me the
+   *  header." */
+  hideWhenEmpty?: boolean;
+  /** Override action shown to the right of the title (e.g. "Restore all"). */
+  rightAction?: ReactNode;
+  children: ReactNode;
+}
+
+export function PaneDrawer({
+  title,
+  count,
+  tone = "default",
+  defaultOpen = false,
+  hideWhenEmpty = false,
+  rightAction,
+  children,
+}: PaneDrawerProps) {
+  const [open, setOpen] = useState(defaultOpen);
+  const isEmpty = typeof count === "number" && count === 0;
+  if (hideWhenEmpty && isEmpty) return null;
+
+  return (
+    <section className={`pane-drawer pane-drawer-${tone} ${open ? "pane-drawer-open" : ""}`}>
+      <header className="pane-drawer-head">
+        <button
+          type="button"
+          className="pane-drawer-toggle"
+          onClick={() => setOpen(o => !o)}
+          aria-expanded={open}
+        >
+          <span className="pane-drawer-caret" aria-hidden="true">
+            {open ? "▾" : "▸"}
+          </span>
+          <span className="pane-drawer-title">{title}</span>
+          {typeof count === "number" ? (
+            <span className="pane-drawer-count">{count}</span>
+          ) : null}
+        </button>
+        {rightAction ? <div className="pane-drawer-action">{rightAction}</div> : null}
+      </header>
+      {open ? <div className="pane-drawer-body">{children}</div> : null}
+    </section>
+  );
+}