feat(simple-editor): node_type bug fix + inline library authoring + back nav

Bucket 1 — Generation bug fix
- post-migrate.py for 19.0.18.8.0 promotes flat 'step' children of
  recipes to 'operation' so fp.job._generate_steps() picks them up.
  Filter is narrow: only direct children of node_type='recipe' get
  flipped, tree-editor sub-steps (parent.node_type='operation') are
  untouched. Idempotent. Posts an audit chatter note on each affected
  recipe.
- Simple Editor controller hardcodes node_type='operation' on insert
  + snapshot-import path so future recipes start correct.

Bucket 2 — Inline library authoring
- 6 new JSONRPC routes (/fp/simple_recipe/library/load + save +
  seed_defaults + input/{add,write,remove}, /fp/simple_recipe/tank/list).
- + New Step button in the right pane opens an inline form with name /
  kind / icon / instructions / stations / flags / prompts table.
- Pencil icon on each library row reopens the same form prefilled.
- Step Kind picker leads with 'Generic — no automatic behaviour'.
- 'Seed defaults from kind' calls action_seed_default_inputs server-side
  for kinds that have curated default prompts.

Bucket 3 — Back nav
- '← Recipes' button in the header (or '← Part' when opened from
  Process Composer) mirrors recipe_tree_editor.js, with
  clearBreadcrumbs:true to avoid stack pollution.

Verified on entech: LGPS1104's 19 'step' children now show as
'operation', migration chatter note posted on the recipe, asset cache
busted.

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

fusion_plating/fusion_plating/migrations/19.0.18.8.0/post-migrate.py

@@ -0,0 +1,104 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc.
+# License OPL-1 (Odoo Proprietary License v1.0)
+"""Post-migration for 19.0.18.8.0 — Simple Editor node_type fix.
+
+Background
+----------
+The Simple Recipe Editor's controller used to insert library templates
+into a recipe with `node_type='step'` directly under the recipe root.
+But fp.job._generate_steps() (in fusion_plating_jobs/models/fp_job.py)
+only creates fp.job.step rows for nodes whose node_type is 'operation'.
+Top-level 'step' children of a recipe were silently skipped, meaning
+Simple-Editor recipes generated zero job steps — no traveller content,
+no shopfloor tablet entries, no CoC moves.
+
+Fix
+---
+Promote every `step` node whose direct parent is a `recipe` to
+`node_type='operation'`. Tree-editor authored 'step' nodes (which sit
+under `operation` parents) are left untouched — the filter is on
+`parent.node_type='recipe'`.
+
+Idempotent: a second run finds no `step` children of recipes and is
+a no-op. Posts a chatter note on each affected recipe so QA / clients
+have a paper trail.
+"""
+
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+_AUDIT_BODY = (
+    '<p><strong>Recipe migrated to v19.0.18.8.0 step layout.</strong></p>'
+    '<p>Step nodes that were direct children of this recipe (Simple '
+    'Editor authoring) have been promoted to operation nodes so they '
+    'generate work-order steps correctly. No data was lost — only '
+    '<code>node_type</code> changed.</p>'
+    '<p>If this recipe was authored via the Tree Editor with explicit '
+    'sub-process / operation hierarchy, this migration was a no-op '
+    'for it.</p>'
+)
+
+
+def migrate(cr, version):
+    if not version:
+        return
+    from odoo.api import Environment, SUPERUSER_ID
+    env = Environment(cr, SUPERUSER_ID, {})
+
+    # Find recipe ids whose direct children include any 'step' rows.
+    # We need this list BEFORE we flip the rows so we can post chatter
+    # afterwards.
+    cr.execute("""
+        SELECT DISTINCT parent.id
+        FROM fusion_plating_process_node parent
+        JOIN fusion_plating_process_node child
+          ON child.parent_id = parent.id
+        WHERE parent.node_type = 'recipe'
+          AND child.node_type = 'step'
+    """)
+    affected_recipe_ids = [r[0] for r in cr.fetchall()]
+
+    if not affected_recipe_ids:
+        _logger.info(
+            "Sub Simple-Editor migration: no flat-step recipes found, "
+            "nothing to do."
+        )
+        return
+
+    # Flip the node_type. Filter is intentionally narrow — only direct
+    # children of a recipe get promoted. Tree-editor sub-step rows
+    # (parent.node_type='operation') are untouched.
+    cr.execute("""
+        UPDATE fusion_plating_process_node child
+        SET node_type = 'operation'
+        WHERE child.node_type = 'step'
+          AND child.parent_id IN (
+              SELECT id
+              FROM fusion_plating_process_node
+              WHERE node_type = 'recipe'
+          )
+    """)
+    flipped = cr.rowcount
+    _logger.info(
+        "Sub Simple-Editor migration: promoted %s step nodes to "
+        "operation across %s recipes.",
+        flipped, len(affected_recipe_ids),
+    )
+
+    # Post a chatter note on each affected recipe (best-effort).
+    Node = env['fusion.plating.process.node']
+    for recipe in Node.browse(affected_recipe_ids):
+        try:
+            recipe.message_post(
+                body=_AUDIT_BODY,
+                message_type='notification',
+                subtype_xmlid='mail.mt_note',
+            )
+        except Exception as e:
+            _logger.warning(
+                "Failed to post audit note on recipe %s: %s",
+                recipe.id, e,
+            )