This PR adds joined, leaving, mute, and unmute sound effects to Zed. 

Release Notes:

- Added joined, leaving, mute, and unmute sound effects (preview-only)

As part of an optimization in
https://github.com/zed-industries/zed/pull/2663, I changed the way that
the worktree ignores FS events within unloaded directories. But this
accidentally prevented us from detecting some events that occur inside
of `.git` directories.

In this PR, I've made further tweaks to which FS events we can ignore.
We now explicitly opt *in* to scanning `.git` (shallowly) directories
(even though they are ignored). Note that we still don't recursively
scan the git directory (including all of the files inside `objects`
etc). This seems like the correct amount of work to do, and from my
testing (and our unit tests that use the real FS and real git
repositories), it seems to work correctly.

Release Notes:

- Fixed a bug where Zed would not detect some git repository changes
(preview only).

Fixes: https://github.com/zed-industries/community/issues/1712

The keymaps were adding in a `"cmd-enter": "editor::NewlineBelow",`
entry in the context of `Editor`, and this was clobbering the assist
command in the assistant panel context. Zed now defines this command in
the default keymap under the context of `"context": "Editor && mode ==
full"`. All I needed to basically do was remove that command from the
keymaps. I also removed the `"cmd-shift-enter": "editor::NewlineAbove"
from the `Editor` context in those keymaps as wel, as it is also defined
in the default keymap.

Release Notes:

- Fix bug preventing the `assistant: assist` command from working in
certain keymaps

Release Notes:

- Fixed a performance problem that could occur when a language server
requested to watch a set of files (preview only).

[[PR Description]]

Release Notes:

- Fixes project panel active state that was incorrectly removed.

Release Notes:

* Fix a bug where project panel entries would not be styled correctly
(preview only)

This PR implements
https://www.figma.com/file/pLq7dvhx2mFeWFOedXpUQ5/Project-%E2%80%93-Collaboration-UI?type=design&node-id=666%3A8610&t=XFGk6KEtTCFXBvCQ-1

Release notes:
- [x] Redesigned collaboration UI
- [x] Added voice support

Fix downloading Elixir being broken

Release Notes:

- N/A
(Should be mentioned in 0.92.x)

/cc @as-cii  @nathansobo  

Release Notes:

- N/A

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

This is a mix of styling and behavioral improvements to the assistant
that we wanted to land before shipping today.

Release Notes:

- N/A

Bypass system help menu shortcut at the app delegate level to achieve this.

Co-Authored-By: Antonio Scandurra <antonio@zed.dev>

Also: Increase right margin on token count to space it from the scrollbar.

Co-Authored-By: Antonio Scandurra <antonio@zed.dev>

Co-Authored-By: Antonio Scandurra <antonio@zed.dev>

Co-Authored-By: Antonio Scandurra <antonio@zed.dev>

Co-Authored-By: Antonio Scandurra <antonio@zed.dev>

Closes
https://linear.app/zed-industries/issue/Z-352/high-memory-usage-from-fs-scanning-if-project-contains-symlinks-that

### Background

Currently, when you open a project, Zed eagerly scans the directory,
building an in-memory representation of all of the files and directories
within. This scanning includes all git-ignored files and follows any
symlinks. When any directory changes on disk, Zed recursively rescans it
in order to keep its in-memory representation up-to-date. When
collaborating, all of these files are replicated to all guests.

Right now, there are some performance problems associated with the
maintenance of this filesystem state:
* For various reasons, some projects contain symlinks that point out to
large folders like `$HOME`, which itself contains many symlinks that
point to the same large directory. When these projects are opened, the
worktree scans endlessly, using more and more memory.
* Some git-ignored directories (like `target` in a rust project) contain
*many* more files than are actually tracked in the git repository. These
files often change as a result of saving, (e.g. because the compiler
runs). Maintaining in memory all of these paths isn't useful to the
user, and causes significant CPU usage on every save. Most importantly,
when collaborating sending all of these changes to guests can be slow,
and can delay all other RPC messages.

### Change

This PR changes the worktree's filesystem-scanning logic to be *lazy*
about scanning two types of directories:
* git ignored directories
* "external" directories (those that are canonically located outside of
the worktree root, but accessed via symlinks)

The laziness works as follows. When, during a recursive scan, a
directory is found that falls into one of the above 2 categories, that
directory is marked as "unloaded". The directory might later be scanned,
if some explicit operation is performed within it (like opening a
buffer, or creating a file), if any collaborator expands that directory
in their project panel, or if an LSP requests that it be watched.

### Results

When collaborating on the `zed` folder:

| metric | before | after |
|-------|--------|------|
| # `worktree_entries` in collab db initially | 154,763 |  77,679 |
| # `worktree_entries` in collab db after 5 saves | 181,952 | 77,679
(nothing new to scan) |
| app memory footprint (host) | 260MB | 228.5 MB  |

The db thing is a win, because reading and writing to the
`worktree_entries` table is one of the most expensive thing that the
`collab` server does.

There's also generally lower background CPU usage after every save,
because we don't need to recursively rescan directories inside of
`target`.

### Limitations

We still end up scanning some unnecessary directories (like
`target/debug/build/zed-b612db829aeac16e/out`) because the LSP instructs
us to watch those.

### To do:

* [x] Expand parent directories of any path opened via LSP
* [x] Avoid creating orphaned entries when FS events happen inside of
unscanned directories
* [x] Scan any newly-non-ignored directories after gitignore changes
* [x] Emit correct events for newly-discovered paths when expanding dirs
* [x] GC the set of expanded directory ids when dirs are removed
* [x] Don't include "external" entries in file-finder
* [x] Expand any directories watched by LSP
* [ ] manual testing and profiling

### Release Notes:

- Fixed a bug where Zed would use excessive memory when a project folder
contained symlinks pointing to directories outside of the project.
- Reduced Zed's memory and CPU usage when working in folders containing
many git-ignored files.

Fixes
https://linear.app/zed-industries/issue/Z-2481/heex-this-snippet-triggers-a-hard-crash

Release Notes:

- Fixed a crash that would sometimes occur when editing a HEEx file
([#1703](https://github.com/zed-industries/community/issues/1703)).

Add missing livekit info

I forget how to do this every single time 😅 Please update anything that
is incorrect!

[[PR Description]]

Release Notes:

- N/A