[BUG] Webview gray screen on long tasks: file-edit tool messages ship the entire pre-edit file (originalContent) on every state push #1885

Problem (one or two sentences)

File-edit tool messages embed originalContent, the full pre-edit file text, in their JSON text. Every message posted to the webview carries it, so the webview heap grows with the sum of all edited files' sizes and eventually turns gray (OOM).

Context (who is affected and when)

Users on long-running or multi-turn tasks that edit many or large files. The state payload keeps growing with each edit, and the webview holds all of it in memory even though originalContent is only needed when the user opens a diff in the File Changes panel. Related gray-screen reports: #1675, #448.

Reproduction steps

1. Zoo Code 3.84.0, any provider. Start a task that edits many large files (or one with a very long history).
2. Keep the task running so that clineMessages accumulates many tool messages containing originalContent.
3. Watch the webview heap (DevTools → Memory) grow with each edit. On long sessions, the chat panel turns gray.

Expected result

The webview receives only what it needs to render. The pre-edit file content is fetched on demand.

Actual result

Each file-edit tool message includes the whole original file in every state push, so webview memory scales with total edited file size and can end in a gray screen.

Variations tried (optional)

A fix is on branch fix/webview-omit-original-content:

• The extension host replaces originalContent with originalContentLength before posting messages to the webview.
• FileChangesPanel requests the content on demand through a new originalContent message.
• It includes unit tests and scripts/gray-screen/* heap-measurement tooling.

App Version

3.84.0

API Provider (optional)

Not Applicable / Other

Model Used (optional)

N/A

Related issues

• [BUG] Gray Screen #1675 – [BUG] Gray Screen (open, same symptom on long tasks)
• [BUG] Completely crashes and turns into a blank grey screen during autonomous tasks. #448 – Blank grey screen during autonomous tasks (closed)
• fix(webview): throttle state pushes to prevent gray screen OOM at high message counts #629 – Throttle state pushes to prevent gray screen OOM (closed; reduced push frequency, not payload size)
• feat(webview): incremental clineMessages delivery for focused task #630 – Incremental clineMessages delivery for the focused task (open; complementary, targets payload size via a different approach)