Editable cell-based JupyterNotebookView + read-only output rendering

[evelyn-with-warp]

Description

Implements the view slice of the editable, cell-based Jupyter .ipynb feature, building on the committed lossless NotebookDoc model. All behavior is gated (by the routing chokepoint, on the integration branch) behind FeatureFlag::JupyterNotebookEditing.

JupyterNotebookView parses content via NotebookDoc::parse and renders each cell as an editable surface:

• Markdown cells → editable rendered markdown (RichTextEditorView/NotebooksEditorModel), serialized back to CellDoc.source on edit.
• Code cells → editable, syntax-highlighted CodeEditorView using NotebookDoc::language(); source stored verbatim.
• Outputs → read-only beneath code cells (stream / text/plain / ANSI-stripped tracebacks as preformatted text; image/png/image/jpeg decoded inline; invalid base64 → placeholder; display-only size guards that never alter saved bytes).

Editing only updates the edited cell's source (user-originated edits only); saved outputs and untouched cells are never mutated. Cell structural ops (insert/delete/move/convert). Robust fallback: unparseable .ipynb shows raw editable text and emits RawRequested so the host opens the real code editor — never blank, never panics.

This is edit-only: no kernel, no execution.

Main files to review

• app/src/notebooks/file/jupyter/mod.rs — JupyterNotebookView (View + Entity + TypedActionView + BackingView), edit→model sync, dirty tracking, structural ops, public API + events.
• app/src/notebooks/file/jupyter/output.rs — strip_ansi, classify_outputs, image decode + display-only size guards.

Minor file changes

• app/src/notebooks/file/mod.rs — adds pub(crate) mod jupyter; so the routing/pane can host the view.
• app/src/notebooks/file/jupyter/{mod_tests.rs, output_tests.rs} — unit/view tests.

Public API (for the routing/integration branch)

new(content, path, ctx), set_content, to_json, is_dirty, mark_saved, request_save, path, title, pane_configuration. Events: Dirtied, SaveRequested { json }, RawRequested { json }, Focused, Pane(PaneEvent). BackingView::PaneHeaderOverflowMenuAction = JupyterNotebookAction.

Validation

• cargo check -p warp --tests: passes (no errors).
• cargo nextest run -p warp jupyter: 19/19 pass.
• ./script/format: clean.
• cargo clippy -p warp --tests: the only findings in this module are never used/constructed dead-code — expected because routing isn't wired on this branch (same class as the base branch's currently-unused ipynb_model); resolves once the integration branch wires JupyterNotebookView::new + NotebookDoc::parse.

Note: this is one half of a parallel split; the orchestrator integrates this with the routing/pane branch into a single combined PR (full presubmit/clippy clean after merge).

Conversation: https://staging.warp.dev/conversation/7eb55c0a-58d5-43e8-88d7-1deda8c567a8

Run: https://oz.staging.warp.dev/runs/019e9a20-4cd6-7283-8e9d-3b233cbd8a21

This PR was generated with Oz.