Co-authored-by: s1n7ax <18459807+s1n7ax@users.noreply.github.com>

Setup:enrich_config asserts that mainClass is present, but attach
configs don't have one and don't need one — the JVM is already running
and chose its own main class, classpath, and java executable. The
assert fires before any check on request type, making every attach
config in nvim-dap fail unless callers pre-populate dummy values for
the five fields the early-return checks.

Adding an early return for `request == 'attach'` skips the
launch-specific enrichment (build_workspace, classpath resolution,
java executable resolution) which are all meaningless for an already-
running JVM.

Reproduction: register a Java attach config in dap.configurations.java
with type='java', request='attach', hostName='127.0.0.1', port=5005,
then :DapContinue. Today it errors with:

    To enrich the config, mainClass should already be present
    .../java-dap/setup.lua:54

After this fix, the attach proceeds and dap-ui opens against the
running JVM as expected.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

client-command-handlers.lua:21 used action.rename(params) (dot)
instead of action:rename(params) (colon). Since Action:rename is
defined with self, the dot-call passed params as self and left the
actual params argument as nil, causing action.lua:28 to error with
"bad argument #1 to 'ipairs' (table expected, got nil)".

All other handlers in this file already use : when calling into
Action:* methods. This brings RENAME_COMMAND in line with them.

Reproduction: in any Java file with jdtls attached, trigger a
refactoring that produces a follow-up rename (e.g. "Extract to
constant" on a string literal). jdtls fires RENAME_COMMAND with
the new symbol's location, and the handler errors before the
rename UI opens. After this fix, the rename UI opens as expected.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* chore(test): replace unit-style specs with e2e integration tests

Old specs only checked LSP attach/capabilities against an empty buffer.
New integration_spec runs against a real Maven fixture project (copied
to a temp dir so root markers resolve correctly) and exercises plugin
features end-to-end: jdtls attach, extension bundling, project import,
dap config, diagnostics, built-in runner, test runner, report viewer,
profile UI and runtime switching.

Closes #497

* fix(pkgm): downloads and extractions fail on Windows when 'shell' is pwsh

vim.fn.system() with a command string is parsed by &shell; nvim nightly
on Windows defaults &shell to pwsh, breaking cmd.exe-style quoting.
Pass argv lists so no shell is involved.

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>