fix(web): the timeline scrolls only as far as its content

docs/fork/0012-timeline-scrolls-only-as-far-as-its-content.md

@@ -0,0 +1,42 @@
+# 0012: The timeline scrolls only as far as its content
+
+- PR: [TrogonStack/t3code#21](https://github.com/TrogonStack/t3code/pull/21)
+- Status: active
+
+## What you can do now
+
+- Drag the timeline scrollbar and land where the thumb says you will. A long
+  thread no longer grows an empty region below the last message that the
+  scrollbar still counts, so the thumb stays proportional to the conversation
+  instead of shrinking to a sliver.
+- Keep a thread open all day without its scroll range drifting. The dead space
+  used to compound with every turn, several times over, until scrolling to the
+  bottom meant travelling multiples of the thread's real height through
+  nothing.
+- Flick to the end on a phone and stop at the last message rather than
+  somewhere in the blank area past it.
+
+## Why
+
+The timeline is the one surface a user never leaves, and its scrollbar is how
+they judge how much thread there is. When the scroll range says a thread is
+eight times longer than it is, every estimate the user makes from it is wrong,
+and the flick that should reach the newest message lands nowhere.
+
+It also degraded the longer someone stayed, which is the worst shape for this
+kind of bug: the threads worst affected are exactly the ones people care most
+about, and closing and reopening the thread was the only way out. That is not
+something we can ask of people who drive agents all day.
+
+## Upstream considerations
+
+This one is not going upstream, by our choice: it lives in a patch against a
+third-party list dependency rather than in T3 Code's own code, so there is no
+upstream T3 Code change to submit. The fix belongs to the list library, and we
+are carrying it locally instead of taking on that project's release cycle.
+
+The rebase burden is small and self-contained. It survives a sync untouched
+unless the dependency version moves; a version bump means regenerating the
+patch, and the affected code was unchanged in the next upstream release, so it
+should reapply. Anyone bumping that dependency needs to confirm the fix is
+still present rather than assume the new version carries it.

docs/fork/README.md

@@ -27,12 +27,19 @@ Each entry uses these sections:
 
 ## Ledger
 
-| #    | Divergence                                                                                      | PR                                                                                                         | Status |
-| ---- | ----------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- | ------ |
-| 0003 | [Native subagent threads for Claude orchestrators](./0003-native-subagent-threads.md)           | [#3](https://github.com/TrogonStack/t3code/pull/3)                                                         | active |
-| 0006 | [Fork schema on its own migration ledger](./0006-fork-migration-ledger.md)                      | [#13](https://github.com/TrogonStack/t3code/pull/13), [#16](https://github.com/TrogonStack/t3code/pull/16) | active |
-| 0007 | [API-key Codex installs are not reported as broken](./0007-codex-api-key-auth-is-supported.md)  | [#15](https://github.com/TrogonStack/t3code/pull/15)                                                       | active |
-| 0008 | [Drop a folder on the sidebar to add a project](./0008-drop-a-folder-to-add-a-project.md)       | [#17](https://github.com/TrogonStack/t3code/pull/17)                                                       | active |
-| 0009 | [Grok reports the account it is signed in as](./0009-grok-reports-its-authenticated-account.md) | [#18](https://github.com/TrogonStack/t3code/pull/18)                                                       | active |
-| 0010 | [Pull request conventions of our own](./0010-fork-pull-request-conventions.md)                  | [#19](https://github.com/TrogonStack/t3code/pull/19)                                                       | active |
-| 0011 | [Follow the background work a thread left running](./0011-follow-background-work.md)            | [#20](https://github.com/TrogonStack/t3code/pull/20)                                                       | active |
+- **0003** [Native subagent threads for Claude orchestrators](./0003-native-subagent-threads.md)
+  active, [#3](https://github.com/TrogonStack/t3code/pull/3)
+- **0006** [Fork schema on its own migration ledger](./0006-fork-migration-ledger.md)
+  active, [#13](https://github.com/TrogonStack/t3code/pull/13), [#16](https://github.com/TrogonStack/t3code/pull/16)
+- **0007** [API-key Codex installs are not reported as broken](./0007-codex-api-key-auth-is-supported.md)
+  active, [#15](https://github.com/TrogonStack/t3code/pull/15)
+- **0008** [Drop a folder on the sidebar to add a project](./0008-drop-a-folder-to-add-a-project.md)
+  active, [#17](https://github.com/TrogonStack/t3code/pull/17)
+- **0009** [Grok reports the account it is signed in as](./0009-grok-reports-its-authenticated-account.md)
+  active, [#18](https://github.com/TrogonStack/t3code/pull/18)
+- **0010** [Pull request conventions of our own](./0010-fork-pull-request-conventions.md)
+  active, [#19](https://github.com/TrogonStack/t3code/pull/19)
+- **0011** [Follow the background work a thread left running](./0011-follow-background-work.md)
+  active, [#20](https://github.com/TrogonStack/t3code/pull/20)
+- **0012** [The timeline scrolls only as far as its content](./0012-timeline-scrolls-only-as-far-as-its-content.md)
+  active, [#21](https://github.com/TrogonStack/t3code/pull/21)