Release detection: exclude test classes/functions from dead code count

[zenprocess]

Problem

The new release detection (from #2) correctly scans for unwired symbols at tag time, but flags test classes and test functions as "dead code." Test functions like test_rebase_branch_success and test classes like TestParseCriteria are invoked by pytest, not by application code — they're not dead.

This inflates the count significantly: v3.3.0 shows 169 "unwired symbols" but most are test functions. The actual dead application code is much smaller.

Fix

Exclude symbols matching these patterns from the dead code count:

• Functions starting with test_
• Classes starting with Test
• Functions named pytest_* (pytest hooks)
• Files under tests/ directory
• Fixtures (@pytest.fixture)

Report test symbols separately if at all:

v3.3.0: 12 unwired application symbols, 157 new test symbols (excluded)

Evidence

From today's scan, v3.3.0 flagged: TestParseCriteria, test_bullet_items, test_skips_short_lines, TestHeuristicCompile, test_test_keyword_shell_check — all test code, all correctly invoked by pytest.