fix(tests): stop the SDD skill test flaking on timing and prose case

tests/claude-code/test-subagent-driven-development.sh failed
intermittently for two independent reasons:

- Budget mismatch: the file runs 9 prompts with a 90s timeout each
  (810s worst case) inside the runner's 600s per-file ceiling, so slow
  backend days produced spurious timeouts. Raise the runner default to
  900s and fix the help text, which claimed the default was 300.
- Case-sensitive prose matching: the assert helpers grepped free-form
  model output case-sensitively, but models capitalize the skill's own
  headings — observed failures include "Do Not Trust the Report"
  missing pattern "not trust" and a structured answer missing
  "First:.*spec.*compliance". Match case-insensitively in
  assert_contains/assert_not_contains/assert_count/assert_order, widen
  two Test 5 keyword patterns to phrasings observed in real runs, and
  make assert_order dump the output on failure the way assert_contains
  already does, so the next flake is diagnosable.

Observed 3 failures across 4 runs before the change (timeout, two
distinct pattern misses); 3/3 consecutive full runs pass after it.

tests/claude-code/run-skill-tests.sh

@@ -25,7 +25,8 @@ fi
 # Parse command line arguments
 VERBOSE=false
 SPECIFIC_TEST=""
-TIMEOUT=600  # Default 10 minute timeout per test
+TIMEOUT=900  # Per-test-file budget; must exceed the file's worst case
+             # (test-subagent-driven-development.sh: 9 prompts x 90s each)
 RUN_INTEGRATION=false
 
 while [[ $# -gt 0 ]]; do
@@ -52,7 +53,7 @@ while [[ $# -gt 0 ]]; do
             echo "Options:"
             echo "  --verbose, -v        Show verbose output"
             echo "  --test, -t NAME      Run only the specified test"
-            echo "  --timeout SECONDS    Set timeout per test (default: 300)"
+            echo "  --timeout SECONDS    Set timeout per test (default: 900)"
             echo "  --integration, -i    Run integration tests (slow, 10-30 min)"
             echo "  --help, -h           Show this help"
             echo ""