Problem:

- annotation-usage-error and code-style-check are disabled.
- vim.inspect relies on a dummy self-assignment for docgen, and its help
  omits parameter and option details.
- LuaLS fallback types obscure iterator inference.
- Docgen hardcodes public function names and appends separately sorted
  files, leaving shared helpers under the inspector heading.

Solution:

- Enable annotation-usage-error and code-style-check, and fix misplaced
  annotations.
- Document vim.inspect's callable module directly, removing the dummy
  assignment. Describe its parameters, option defaults and process
  callback.
- Remove LuaLS iterator fallbacks, correct iterator signatures and check
  values that the improved inference identifies as optional.
- Parse callable modules, require bindings and parent module references.
  Derive public names and inherited function docs from these links,
  including missing help for vim.async.semaphore() and vim.version().
- Export vim.lsp.tagfunc directly with lazy loading and document its
  implementation instead of maintaining a wrapper.
- Group files in section_order, replacing append_only and merge_files.
  Merge declarations before sorting each section, placing shared helpers
  in the main vim section and keeping vim.inspect in alphabetical order.
- Add basic parser coverage for callable modules and module links.

AI-assisted

AI-assisted

Enable checks for unused code, deprecated calls, return types, and
annotations.

Fix the warnings and replace the deprecated highlight function. Keep
exceptions where old APIs are still needed or the checker gets it wrong.

AI-assisted

- call-non-callable
- missing-fields
- redefined-label
- redefined-local
- undefined-field
- unreachable-code

Promote redefined-local and unreachable-code to warnings.

Fix DOS line-ending handling for multiline semantic tokens, and support
intersection types in the help parser.

AI-assisted

Problem: LuaLS struggles with the generics used in Nvim's runtime,
requiring broad diagnostic suppressions. Indexing is also slow.

Solution: Use EmmyLua for type checks in the build and CI. It offers
more sophisticated type checking, substantially better support for
generics, and much better flow analysis.

Correct the affected annotations. Use `@internal`, supported directly by
EmmyLua, instead of `@nodoc` for shared internal declarations, and
support it in the help parser.

AI-assisted

Problem: Every LSP capability that sends a request on a document change
to update its state was using its own buffer-local autocmd to do so.
That means there is a separate autocmd per buffer per active
capability/feature, and the actual code inside the autocmd callback was
virtually identical. The same problem occurred for capabilities that had
components to draw on the screen that had their own decoration providers.

Solution: Introduce a central `LspNotify` autocmd and decoration
provider in the capability module itself. New base class methods
`on_close` and `on_change` that take a client_id have been provided, for
`didClose` and `didOpen`/`didChange` notifications respectively. New
base class method `on_win` that takes topline and botline has been
provided to add extmarks or perform other work when lines of a buffer
are being drawn.

The autocmd callback loops through each active capability instance for
the buffer and calls a corresponding method with the triggering
client_id if it is currently attached to the buffer that triggered the
autocmd. The decoration provider just calls on_win for all active
capabilities on the buffer.

This slightly tweaks folding range to make use of these new client-id
specific callbacks.

Problem:
Inlay hints used separate global and per-buffer bufstates tables and
bespoke global autocmds for managing the inlay hint state across buffers
and clients, duplicating the lifecycle logic already provided by the
Capability framework. This caused inconsistencies in how client state
was handled and inlay hint state lifecycle was managed compared to other
LSP features.

Solution:
Replace the ad-hoc bufstate tracking and global autocmds in
vim.lsp.inlay_hint with a proper InlayHint subclass of Capability.

This also refactors the way inlay hint state is managed and fixes bugs I
found while doing this:

1. For each line with inlay hints, the list of the hints along with
   whether they have been applied is stored in a current result on the
   client state. This allows the on_win decorator to clear all inlay
   hints for an old document version once, and then re-add the new
   version's hints line-by-line as they are drawn to the screen,
   modeling the semantic tokens module.
2. It fixes problems with mixing results from multiple clients attached
   to the buffer by fully moving each client's state to its own table.
   Previously, only the most recent document version used to populate a
   line's inlay hints was stored, but there was no distinction for which
   client the hints may have come from. (Fixes #36318)
3. It fixes the workspace/inlayHint/refresh server->client notification
   behavior. Previously it would only re-request inlay hints for buffers
   currently displayed in a window but would not invalidate them in
   non-displayed buffers (or provide any mechanism for those buffers to
   re-request at a later time). Model semantic token module here again
   by invalidating all buffers, and adding a BufWinEnter autocmd to
   refresh hints.
4. Add a mechanism to cancel in-flight requests if a new request for a
   newer document version is made before the last one returned
5. Handle stale results by simply dropping them.

Problem:
Diagnostic tracking used a separate bufstates table and manual
LspDetach/LspNotify autocmd management via _enable()/_refresh(),
duplicating the lifecycle logic already provided by the Capability
framework. This caused inconsistencies in how client attach/detach and
buffer teardown were handled compared to other LSP features.

Solution:
Replace the ad-hoc bufstate tracking and _enable/_refresh pattern in
vim.lsp.diagnostic with a proper Diagnostics subclass of Capability.
This cleans up a few random places in the main lsp module and client
module that were poking the diagnostics. It also fixes some pre-existing
bugs and inconsistencies that were discovered:

- Refresh diagnostics immediately on attach instead of lazily by the
  first didOpen/didChange notification
- Fix Capability.active lookup in M.enable() to key by it_bufnr instead
  of the filter bufnr
- Set lsp defaults before calling the _text_document_did_open_handler in
  Client:on_attach() so defaults are there before any lsp notification
  occurs
- Log (and return early) on any error from a diagnostic request result
  instead of only returning early for server cancelled errors

Today there is a constraint that these arguments to the enable filter be
mutually exclusive, but I do not know why such a constraint exists (it
is perfectly reasonable to want to enable a capabilility for just one
buffer and just one client).