Tracking #1381: writeDelayMs default is 0 (DEFAULT_WRITE_DELAY_MS) #1386

Tracking issue for upstream PR #1381 (branch fix/write-delay-default).

Part of the file-write safety series — plan: easonLiangWorldedtech/Zoo-Code#33, epic: #1375.

Scope

• writeDelayMs default is now 0 (shared DEFAULT_WRITE_DELAY_MS constant): zero artificial latency on the default write path; the per-user setting and the diagnostics delay are unchanged.
• ClineProvider.getStateToPostToWebview() covered for both the persisted (500) and default (constant) cases.
• DiffViewProvider.spec asserts DEFAULT_WRITE_DELAY_MS instead of a hardcoded 1000 (the hardcoded expectation failed CI after the default flip).

Acceptance

• Default write path has no forced delay
• No user-visible setting change (storage key unchanged)
• CI green (ubuntu unit-test gate)

Status

• PR: OPEN, MERGEABLE — CI green (platform-unit-test ubuntu + windows SUCCESS, codecov/patch SUCCESS, CodeRabbit SUCCESS)