feat(kimi-code): vendor @moonshot-ai/pi-tui (#1254)

* chore(kimi-code): upgrade pi-tui to 0.78.1 and adapt native helpers

Bump @earendil-works/pi-tui from ^0.74.0 to ^0.78.1. pi-tui 0.75.5 replaced its koffi-based Windows VT input with a bundled native helper, and 0.76.0 added a darwin native helper for Terminal.app Shift+Enter.

- SEA build: teach native-deps to collect pi-tui's per-target .node files, drop the koffi registry, and add a native-file-only collect mode so only package.json + the target .node ship (28 -> 2 files).

- Redirect pi-tui's absolute-path native require() into the native-asset cache through the Module._load hook, and extend the native smoke test to actually load the helper.

- npm package: ship pi-tui's native/ directory so macOS Terminal.app Shift+Enter and Windows Shift+Tab keep working for npm installs.

* chore: add changeset for pi-tui upgrade

* chore: vendor @earendil-works/pi-tui 0.80.2

Fork the upstream pi-tui source into packages/pi-tui for local modification. Pristine snapshot of @earendil-works/pi-tui@0.80.2; the apps/kimi-code dependency on ^0.78.1 from npm is left unchanged.

* feat(kimi-code): integrate vendored @moonshot-ai/pi-tui

Replace the npm @earendil-works/pi-tui dependency with the vendored @moonshot-ai/pi-tui workspace package so the fork can be modified locally.

- Point apps/kimi-code imports and native-deps at @moonshot-ai/pi-tui.

- Make pi-tui source-first (exports -> src, publishConfig.exports -> dist, mirroring node-sdk) and strict-clean: bracket access for process.env / named capture groups, an override modifier, and non-null assertions for noUncheckedIndexedAccess.

- Bump the root tsconfig target to ES2024 and enable allowImportingTsExtensions (needed for pi-tui's /v regex and .ts imports, which node --test requires).

- Add packages/pi-tui to flake.nix workspaces and exclude the vendored source from oxlint.

* fix(pi-tui): export package.json for native asset resolution

The SEA native-asset collector resolves the package root via
require.resolve('@moonshot-ai/pi-tui/package.json'). The vendored
package's exports field only exposed ".", which blocked the
"./package.json" subpath and broke build:native:sea with
ERR_PACKAGE_PATH_NOT_EXPORTED.

* chore(kimi-code): sync pi-tui native prebuilds at build time

Copy packages/pi-tui/native prebuilds into apps/kimi-code/native
during build instead of tracking a manual copy in git. Only the
.node prebuilds are copied (not the C sources); the directory is
now a build artifact covered by .gitignore.

* fix(pi-tui): avoid destructive full redraw during streaming

When the first changed line is above the viewport, the differential
renderer fell back to fullRender(true), which clears scrollback and
yanks the user's viewport. On Windows Terminal this jumps to the
absolute top (microsoft/Terminal#20370).

Clamp the diff to the visible viewport when content length is
unchanged (spinner tick / markdown reflow above the viewport), so
streaming no longer triggers a full redraw in those cases. Length
changes still fall back to fullRender to reset the viewport.

* fix(kimi-code): update pi-tui imports in files merged from main

Two files added on main (effort-selector, plugin-command) still
imported the old @earendil-works/pi-tui package name; point them at
the vendored @moonshot-ai/pi-tui.

* chore(nix): update pnpmDeps hash after lockfile regen

* fix(pi-tui): clamp above-viewport diff even when content shrinks

Previously, when the first changed line was above the viewport and
content length changed (e.g. spinner removed at end of streaming), the
renderer fell back to fullRender(true), which clears scrollback and
yanks the viewport to the absolute top on Windows Terminal.

Always clamp the diff to the visible viewport instead, preserving the
user's scroll position. Stale bytes remain in scrollback but are not
visible.

* fix(kimi-code): keep activity placeholder to avoid streaming shrink

When streaming ends, removing the activity spinner shrank the content
by two rows, which (combined with transient→final code highlighting
above the viewport) triggered a destructive full redraw. Keep a one-row
placeholder in the activity pane when idle so the content does not
fully shrink.

* chore: refine streaming scroll changeset wording

* chore: remove obsolete pi-tui native helpers changeset

* chore: add pi-tui changesets and document the pi-tui changelog rule

Add changesets for the fork integration, package manifest export, and
viewport clamp fix so the vendored pi-tui keeps its own changelog.

Update the gen-changesets skill to treat @moonshot-ai/pi-tui as a
special internal package that lists itself instead of the CLI, with a
separate CLI changeset only when the change is user-visible there.

* chore(nix): update pnpmDeps hash after merging main

* fix(changeset): drop private kimi-code-docs from google-genai changeset

.agents/skills/gen-changesets/SKILL.md

@@ -11,6 +11,8 @@ description: Use when generating changesets in the kimi-code repository, includi
 
 All other `@moonshot-ai/*` packages are treated as internal packages, including `@moonshot-ai/kimi-code-sdk`, `agent-core`, `kosong`, `kaos`, `kimi-code-oauth`, `kimi-telemetry`, and `migration-legacy`.
 
+`@moonshot-ai/pi-tui` is a special internal package: it is a private fork (`private: true`) that is never published, but it keeps its own changelog through changesets. It is an exception to Core Rule 4 — see the dedicated section below.
+
 ## Core Rules
 
 1. **Inspect the actual changes first.** Use `git status` / `git diff --name-only` to identify which packages were actually changed.
@@ -176,6 +178,41 @@ Add the server-hosted web UI, including chat layout and session list behaviors.
 Add the server REST and WebSocket APIs that power the web UI.
 ```
 
+## `@moonshot-ai/pi-tui` changes
+
+`@moonshot-ai/pi-tui` is a vendored fork that lives in `packages/pi-tui`. It is `private: true` and is never published, but it is **not** ignored by changesets: changesets versions it and writes `packages/pi-tui/CHANGELOG.md` so the fork keeps its own history. Because it is bundled into the CLI like other internal packages, it is an exception to Core Rule 4 — do **not** list `@moonshot-ai/kimi-code` for a change that only touches pi-tui.
+
+- Changes that only affect pi-tui (build, package, strict-mode cleanup, renderer fixes): list `@moonshot-ai/pi-tui` only. No CLI changeset.
+- If the same change is also user-visible in the CLI (for example a terminal rendering fix that CLI users can see), add a **separate** changeset that lists `@moonshot-ai/kimi-code` with CLI-focused wording, in addition to the pi-tui changeset. Do not mix both packages in one frontmatter — the two changelogs need different wording.
+
+pi-tui-only change:
+
+```markdown
+---
+"@moonshot-ai/pi-tui": patch
+---
+
+Export the package manifest so the bundled binary can locate its native assets.
+```
+
+pi-tui change that is also visible in the CLI (two separate changesets):
+
+```markdown
+---
+"@moonshot-ai/pi-tui": patch
+---
+
+Clamp the differential render to the visible viewport so scrolling up during streaming no longer jumps to the top.
+```
+
+```markdown
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix the transcript jumping to the top when scrolling up through history during streaming output.
+```
+
 ## Red Flags
 
 - You are about to write `major` without asking the user.
@@ -188,3 +225,4 @@ Add the server REST and WebSocket APIs that power the web UI.
 - The wording claims more than the diff actually did.
 - The CLI wording mentions internal package names, class names, or PR numbers.
 - The entry includes real internal identifiers instead of neutral placeholders.
+- A change that only touches `@moonshot-ai/pi-tui` lists `@moonshot-ai/kimi-code` instead of `@moonshot-ai/pi-tui`, or mixes both packages in one frontmatter.