Problem:
Only the stdio channel can "own" a server (self-exit on close). After
:restart the TUI reconnects over a socket, so the restarted server does
not have "self-exit" behavior when the channel closes (e.g. by UI
disconnect, host-terminal close, etc.), which leaves a dangling server.

Solution:
- Introduce `nvim_chan_set`. (`nvim_set_client_info` doesn't fit:
  exposing it to Lua would require a `channel` param, which is not
  backwards-compatible, plus it's awkward because it doesn't merge info.)
- Broadcast per-channel properties in the "restart" UI event as an
  opaque dict (a potentially useful pattern for other UI-events in the
  future).
  - UIs are expected to restore the channel properties on restart.
- `nvim_get_chan_info()` reports "detach".
- Remove `nvim__chan_set_detach()`.

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

Problem: Argument type mismatches are excluded from EmmyLua checks.

Solution: Correct runtime annotations and calls, document local checker
workarounds, and enable the diagnostic.

AI-assisted

AI-assisted

Enable EmmyLua's assign-type-mismatch diagnostic after correcting the
runtime annotations and assignments it flags.

Correct option, tuple, and return types, and use separate locals when a
value changes representation. Add guards and narrow casts where needed
so the runtime passes the stricter check. Regenerate the affected docs.

AI-assisted

Enable EmmyLua's need-check-nil diagnostic and resolve nullable values
through more precise types, explicit invariants, and guards for missing
runtime state. Keep analyzer-specific workarounds local and update the
affected API documentation.

Exclude the bundled re.lua from analysis so its nil-check warnings do
not fail CI.

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:
With the addition of the `:help al` text object, you can now easily
format the whole buffer with `gqal`. However, `vim.lsp.formatexpr` only
uses `textDocument/rangeFormatting` which some language servers (like
gopls) don't support.

Solution:
- Fall back to `textDocument/formatting` if the whole buffer is being formatted
  and the server doesn't support `textDocument/rangeFormatting`.
  - In theory, these two methods should return the same response if the whole
    buffer is being formatted, but I preserved the existing behaviour of
    prioritising `textDocument/rangeFormatting` in case that does not hold (i.e.
    LS bug).
- Also: `vim.lsp.formatexpr` had no tests at all, so actually add tests for it.

Problem: The reuse_client predicate does not pass the target buffer,
preventing decisions from being truly made per buffer.

Solution: Pass the target buffer.