Problem:
An inherited Git index can leave a plugin checkout empty or prevent
updates.

Solution:
Clear GIT_INDEX_FILE for plugin Git commands. Verify installs and
updates preserve the caller environment and index.

AI-assisted
Signed-off-by: Jake Wang <jakezwang@users.noreply.github.com>

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

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

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

Problem:
The `textDocument/documentLink` handler resolves the confirmation buffer
from the request URI and checks it for `nil`, then reads lines from
buffer `0`. When the confirmation buffer is not current, links are
computed from unrelated text and returned against the confirmation
buffer's line numbers, producing missing or misplaced links.

Solution:
Read lines from the resolved `bufnr`.

AI-assisted

Problem: Trying to execute code action on an active plugin without
  updates leads to nothing. It is more useful if code actions "do
  something" on a bigger portion of the confirm buffer.

Solution: Suggest "delete" code action even for active plugins. Trying
  to execute it will first show a confirmation buffer with relevant
  warning of why this might be not a good idea. Confirming will delete
  a plugin.

Problem: There are many Git forges each with a different way of
  constructing permanent links to like commits and tags.

Solution: Add a private utility function that computes these special
  links on the best effort basis.

Problem: In `vim.pack.update()` confirmation buffer it might be useful
  to be able to use `gx` (open link at cursor) when cursor is on
  something like commit or tag.

Solution: Add `textDocument/documentLink` method support for the
  in-process LSP. This may be used by LSP clients and makes `gx`
  automatically work.

  The shortcoming is that this requires tracking how to construct a URL
  from source and commit/tag. Currently only GitHub hosted repositories
  are supported.