feat(container-extensions): true connection status for read and write…

… clients (#24981)

## Description 

Fixes
[AB#17920](https://dev.azure.com/fluidframework/235294da-091d-4c29-84fc-cdfc3d90890b/_workitems/edit/17920)

Currently, `isConnected` for container extensions tells us when the
local client is able to send ops. This is does not represent the true
connection state for read clients, since they can be connected to
service while still unable to send ops. This definiton of 'connected' is
too restrictive for a signal-based container extension like Presence,
since read clients should be considered 'connected' when they are able
to send signals.

To fix this, we pass container connection state to runtime to
circumevent the lie in `Container.setContextConnectedState`, and for
container extensions we replace`isConnected` with `getJoinedStatus`
which can either be "joinedForReading", "joinedForWriting", or
"disconnected". This way container extensions such as Presence are able
to know when there is an active connection to service even in readonly
mode.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

flub fix: Dockerfile policy check fails on Windows (#25100)

## Description

Fixed an issue with flub that only shows up on Windows. The paths we are
checking in Dockerfiles as part of the policy check use foreslashes, but
we build it using paths from the filesystem. This change normalizes the
path to use foreslashes.

Note that we need to make a pass over the other places that build
filepaths to check against file contents. This will be a separate work
item.

feat(api-markdown-documenter): Add documentation domain to mdast tran…

…sformation (#24787)

Updates the library with a new transformation layer that converts the
`DocumentationNode` representation to
[mdast](https://github.com/syntax-tree/mdast), and replaces the
library's custom Markdown rendering with
[mdast-util-to-markdown](https://github.com/syntax-tree/mdast-util-to-markdown).

For an example of how the website build will be updated in response to
these changes, see here:
#25072.

Release notes for 2.51 (#25054)

## Description

Release notes for 2.51.

build(server): Generate release notes for server 7.0.0 (#25010)

This PR generates the release notes for the 7.0.0 server release.

feat(eslint-config-fluid): Promote import rules from `strict` ruleset…

… to `recommended` ruleset (#25007)

Promotes the following rules from the `strict` ruleset to the
`recommended` ruleset:

-
[@typescript-eslint/consistent-type-exports](https://typescript-eslint.io/rules/consistent-type-exports/)
-
[@typescript-eslint/consistent-type-imports](https://typescript-eslint.io/rules/consistent-type-imports/)
-
[@typescript-eslint/no-import-type-side-effects](https://typescript-eslint.io/rules/no-import-type-side-effects/)

These rules together have the potential to optimize bundler behavior, so
prioritizing these across the repo seems like a good idea.

I will integrate into client next week and fix violations. Violations to
these rules are generally easy to resolve via eslint's auto-fix, so
applying them across the repo at once should not be too difficult.

(2) Clean up changesets and generate release notes and changelogs for…

… 2.50 (#24978)

`pnpm flub generate releaseNotes -g client -t minor --outFile
RELEASE_NOTES/2.50.0md ` run after fixing metadata format on a change
set
`pnpm flub generate changelog -g client`

Second command deleted the release note file so I had to add it back
manually.

2.43 change sets (#24895)

## Description

`pnpm flub generate releaseNotes -g client -t minor --outFile
RELEASE_NOTES/2.43.0.md`

commit

`pnpm flub generate changelog -g client`

## Reviewer Guidance

The review process is outlined on [this wiki
page](https://github.com/microsoft/FluidFramework/wiki/PR-Guidelines#guidelines).

Enforcement mode in CSP (#24850)

Seeing only 1 violation in CREM board after recent header changes.
Talked with security team and seems we're not on the hook for that type
of violations. Now turning enforcement mode back on.

build(api-markdown-documenter): Simplify API-Extractor setup (#24800)

This package is versioned and published independently from the rest of
the repo. It was previously set up to use our shared base API-Extractor
configs, which are configured for packages in release groups that
version/publish many packages together.

Specific changes:
- Don't extend shared config
- Remove "lint" config (unused and unneeded)
- Restore rollup generation
- Fix `/beta` export path
- Remove alpha report (this package has no alpha APIs nor export)