fix: allow section_header step type in validation, improve tag input

- Add 'section_header' to VALID_STEP_TYPES in backend validation so
  procedural flows with section headers can be published
- Replace procedural editor's inline tag input with TagInput component
  (supports autocomplete, Tab, comma, semicolon, and paste splitting)
- Add semicolon delimiter support to TagInput component

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

backend/app/core/tree_validation.py

@@ -115,7 +115,7 @@ def _validate_children(children: list[dict[str, Any]], path: str, errors: list[d
 
 # --- Procedural Tree Validation ---
 
-VALID_STEP_TYPES = {"procedure_step", "procedure_end"}
+VALID_STEP_TYPES = {"procedure_step", "procedure_end", "section_header"}
 VALID_CONTENT_TYPES = {"action", "informational", "verification", "warning"}
 
 

frontend/src/components/common/TagInput.tsx

@@ -106,10 +106,14 @@ export function TagInput({
     } else if (e.key === 'Escape') {
       setShowSuggestions(false)
       setSelectedIndex(-1)
-    } else if (e.key === ',' || e.key === 'Tab') {
+    } else if (e.key === ',' || e.key === ';' || e.key === 'Tab') {
       if (inputValue.trim()) {
         e.preventDefault()
-        addTag(inputValue)
+        // Support multiple tags separated by commas or semicolons
+        const parts = inputValue.split(/[,;]/).map(s => s.trim()).filter(Boolean)
+        for (const part of parts) {
+          addTag(part)
+        }
       }
     }
   }
@@ -157,7 +161,20 @@ export function TagInput({
             ref={inputRef}
             type="text"
             value={inputValue}
-            onChange={(e) => setInputValue(e.target.value)}
+            onChange={(e) => {
+              const val = e.target.value
+              // If pasted text contains delimiters, split into tags immediately
+              if (val.includes(',') || val.includes(';')) {
+                const parts = val.split(/[,;]/).map(s => s.trim()).filter(Boolean)
+                const last = parts.pop()
+                for (const part of parts) {
+                  addTag(part)
+                }
+                setInputValue(last || '')
+              } else {
+                setInputValue(val)
+              }
+            }}
             onKeyDown={handleKeyDown}
             onFocus={() => {
               if (inputValue.length >= 1 && suggestions.length > 0) {
@@ -221,7 +238,7 @@ export function TagInput({
 
       {/* Helper text */}
       <p className="mt-1 text-xs text-white/40">
-        {tags.length}/{maxTags} tags. Press Enter or comma to add.
+        {tags.length}/{maxTags} tags. Press Enter, Tab, comma, or semicolon to add.
       </p>
     </div>
   )

frontend/src/pages/ProceduralEditorPage.tsx

@@ -1,10 +1,11 @@
-import { useEffect, useState } from 'react'
+import { useEffect } from 'react'
 import { useParams, useNavigate } from 'react-router-dom'
 import { Save, ArrowLeft, ListOrdered } from 'lucide-react'
 import { treesApi } from '@/api/trees'
 import { useProceduralEditorStore } from '@/store/proceduralEditorStore'
 import { IntakeFormBuilder } from '@/components/procedural-editor/IntakeFormBuilder'
 import { StepList } from '@/components/procedural-editor/StepList'
+import { TagInput } from '@/components/common/TagInput'
 import { toast } from '@/lib/toast'
 
 export function ProceduralEditorPage() {
@@ -33,8 +34,6 @@ export function ProceduralEditorPage() {
     getTreeForSave,
   } = useProceduralEditorStore()
 
-  const [tagInput, setTagInput] = useState('')
-
   // Load tree or init new
   useEffect(() => {
     if (isEditMode && id) {
@@ -95,18 +94,6 @@ export function ProceduralEditorPage() {
     }
   }
 
-  const handleAddTag = () => {
-    const tag = tagInput.trim()
-    if (tag && !tags.includes(tag)) {
-      setTags([...tags, tag])
-      setTagInput('')
-    }
-  }
-
-  const handleRemoveTag = (tag: string) => {
-    setTags(tags.filter((t) => t !== tag))
-  }
-
   if (isLoading) {
     return (
       <div className="flex min-h-[50vh] items-center justify-center">
@@ -187,34 +174,7 @@ export function ProceduralEditorPage() {
             <div className="grid grid-cols-2 gap-4">
               <div>
                 <label className="mb-1 block text-sm font-medium text-white/60">Tags</label>
-                <div className="flex items-center gap-2">
-                  <input
-                    type="text"
-                    value={tagInput}
-                    onChange={(e) => setTagInput(e.target.value)}
-                    onKeyDown={(e) => { if (e.key === 'Enter') { e.preventDefault(); handleAddTag() } }}
-                    placeholder="Add tag..."
-                    className="flex-1 rounded-lg border border-white/10 bg-black/50 px-3 py-2 text-sm text-white placeholder:text-white/30 focus:border-white/30 focus:outline-none focus:ring-1 focus:ring-white/20"
-                  />
-                </div>
-                {tags.length > 0 && (
-                  <div className="mt-2 flex flex-wrap gap-1">
-                    {tags.map((tag) => (
-                      <span
-                        key={tag}
-                        className="inline-flex items-center gap-1 rounded-full bg-white/10 px-2 py-0.5 text-xs text-white/70"
-                      >
-                        {tag}
-                        <button
-                          onClick={() => handleRemoveTag(tag)}
-                          className="text-white/40 hover:text-white"
-                        >
-                          &times;
-                        </button>
-                      </span>
-                    ))}
-                  </div>
-                )}
+                <TagInput tags={tags} onChange={setTags} />
               </div>
 
               <div className="flex items-end pb-1">