feat(workflow-form): embed the read-only workflow preview

[yangzhang75]

What changes were proposed in this PR?

Building on the title-bar frame (#8391), this PR adds the collapsible read-only workflow preview to the Form View, and the read-only support the embedded editor needs (parent issue #8011). Frontend only.

• A "Workflow" strip on the page that opens to show the same workflow editor and mini-map the operator canvas uses, embedded here read-only. It is built the first time the reader opens the strip (a frame after the strip is revealed, so JointJS measures a real size rather than a zero-sized one that misroutes links), then centred.
• structureLocked on the shared workflow-editor: a mode that locks the graph shape (dragging, linking, deleting) without touching the workflow-modification lock the property panel rides on, and suppresses the shared cursor so a read-only view never broadcasts one. It defaults to false, so the operator canvas is unchanged. A container ResizeObserver keeps the paper sized to its own container (the strip toggles it via display:none, which the window-resize handler never hears), and operators already in the graph when this late-mounting editor appears are repainted so a completed run's colours are not missing.
• With the flag on the form renders for any workflow, so the preview shows the graph read-only regardless of the workflow's default view.

The inputs, running and results are added on top of this by later PRs.

Screenshot

The workflow preview open on the read-only page (the "Workflow" strip expanded to the embedded editor + mini-map):

Any related issues, documentation, discussions?

Part of the Form View feature (parent issue #8011); stacked on #8391 (title bar) and #8376 (page shell). Until those merge, this PR's diff includes their commits as well.

How was this PR tested?

Unit tests (vitest): workflow-form.component.spec.ts (direct construction) and workflow-form.rendered.spec.ts (TestBed-rendered template) cover the strip's open/build/close/walk-away behaviour and the rendered bar; the shared workflow-editor.component.spec.ts (106 tests) is unchanged and green, confirming the structureLocked split leaves the canvas untouched. The page component is at 100% of its TypeScript, and every line added to workflow-editor is covered. Three template lines are not exercised: the <texera-workflow-editor> and <texera-mini-map> embed behind *ngIf, which need a real JointJS paper jsdom cannot provide (the editor's own paper code is v8-ignored for the same reason). ng build is clean.

Was this PR authored or co-authored using generative AI tooling?

Yes. Co-authored with Claude (Anthropic), reviewed line by line by the author before submission.

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @PG1204
  You can notify them by mentioning @PG1204 in a comment.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 94.05941% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 94.03%. Comparing base (dcb25ef) to head (6b9d453).

Files with missing lines	Patch %	Lines
...mponent/workflow-form/workflow-form.component.html	86.36%	3 Missing ⚠️
...component/workflow-form/workflow-form.component.ts	96.66%	0 Missing and 2 partials ⚠️
...onent/workflow-editor/workflow-editor.component.ts	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8429      +/-   ##
============================================
- Coverage     94.03%   94.03%   -0.01%     
+ Complexity     4821     4820       -1     
============================================
  Files          1207     1207              
  Lines         49109    49202      +93     
  Branches       5963     5975      +12     
============================================
+ Hits          46180    46266      +86     
- Misses         1461     1464       +3     
- Partials       1468     1472       +4     

Flag	Coverage Δ		*Carryforward flag
access-control-service	81.00% <ø> (ø)		Carriedforward from 71637a1
agent-service	99.32% <ø> (ø)		Carriedforward from 71637a1
amber	89.90% <ø> (-0.01%)	⬇️	Carriedforward from 71637a1
computing-unit-managing-service	73.67% <ø> (ø)		Carriedforward from 71637a1
config-service	87.12% <ø> (ø)		Carriedforward from 71637a1
file-service	87.91% <ø> (ø)		Carriedforward from 71637a1
frontend	96.77% <94.05%> (-0.02%)	⬇️
notebook-migration-service	83.57% <ø> (ø)		Carriedforward from 71637a1
pyamber	98.47% <ø> (ø)		Carriedforward from 71637a1
workflow-compiling-service	77.19% <ø> (ø)		Carriedforward from 71637a1

*This pull request uses carry forward flags. Click here to find out more.

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