chore(spec): per-test wall-clock timing + documentation reporter

The default rspec progress (dots) hides which test is in flight when a
runner stalls. Last week's CI on Ruby 3.4 spent 41 minutes silently
between two examples — the log only shows DEPRECATION warnings before
and after, so the culprit was unidentifiable.

Adds .rspec config (--format documentation, --profile 25) and a
support/timing.rb hook that warns:

  [timing] start <full description>
  [timing] N.NN s <pass|fail> <full description>

on each example. Two effects:

* A hung runner now leaves a 'start ...' breadcrumb so the next person
  knows exactly which spec was mid-flight.
* End-of-run --profile output lists the 25 slowest, which surfaces the
  flake culprits without having to scan the whole transcript.

Author: nijeesh-stream

.rspec

@@ -0,0 +1,3 @@
+--require spec_helper
+--format documentation
+--profile 25

spec/support/timing.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+# Per-test wall-clock timing emitted to STDOUT so CI logs surface which
+# example is in flight when a runner stalls. The default `--format
+# documentation` reporter prints test names but not timing; `--profile`
+# only summarises at the end (no help when the run hangs before reaching
+# the summary). This hook fills the gap: every example logs
+# `[timing] start ...` on enter and `[timing] N.NN s ...` on exit with
+# its full description path, so an unattended runner stuck mid-test
+# leaves a clear breadcrumb.
+RSpec.configure do |config|
+  config.before(:each) do |example|
+    example.metadata[:timing_started_at] = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+    warn "[timing] start #{example.full_description}"
+  end
+
+  config.after(:each) do |example|
+    started_at = example.metadata[:timing_started_at]
+    next unless started_at
+
+    elapsed = Process.clock_gettime(Process::CLOCK_MONOTONIC) - started_at
+    status = example.exception ? 'fail' : 'pass'
+    warn format(
+      '[timing] %<elapsed>.2f s %<status>s %<description>s',
+      elapsed: elapsed,
+      status: status,
+      description: example.full_description
+    )
+  end
+end