feat(py): step 3 — full latprobe package with --verbose flag

Adds the complete Python port of the Go latprobe tool plus diagnostic
verbose output that the Go version does not yet have.

Package (python/latprobe/):
- probe.py: raw-socket HTTP timing with CertInfo/VerboseDetail dataclasses;
  TTFB loop accumulates to \r\n\r\n so headers are parseable without changing
  t_first_byte semantics; captures resolved IP, TLS version/cipher/bits,
  verified cert (via getpeercert()), and all response headers when verbose=True
- aggregate.py: summarize() → per-phase min/avg/max PhaseStats
- cli.py: injectable run(args,stdout,stderr)->int; argparse with injected
  streams; ThreadPoolExecutor concurrency across URLs; four text-rendering
  branches; JSON output; worst-exit-code accumulation; -v/--verbose flag
  appends IP/TLS/cert/header block after every timing table; JSON extended
  with "verbose" object (omitted when flag absent)
- duration.py: parse Go-style duration strings (10s, 500ms, 2m, bare seconds)
- Exit codes: 0 ok, 1 usage, 2 dns, 3 connect, 4 timeout, 5 tls, 6 http≥400

Tests:
- test_probe.py: 18 hermetic tests (success, 404, DNS/connect/timeout/scheme
  failures, partial-phase invariants, verbose detail fields)
- test_cli.py: 38 hermetic tests (usage errors, single/aggregate/failure text,
  worst-code, --fail, JSON schema/ordering/grouping, verbose text and JSON)
- test_integration.py: 45 tests against live internet services (badssl.com for
  TLS errors, real cert/IP/header validation in verbose mode)

Makefile: PYTHONPATH fix, fnmatch pattern test_[!i]*.py to exclude
integration tests from py-test, new py-test-integration target

Docs: docs/usage/py-latprobe.md, python/configs/usage-latprobe.md (runnable
reference with captured output), plans for both the package and verbose feature

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -4,6 +4,52 @@ All completed features are logged here in reverse-chronological order.
 
 ---
 
+## 2026-07-01 12:55 — `--verbose` / `-v` flag for `latprobe` (Python)
+
+- `-v`/`--verbose` flag added to the `latprobe` CLI
+- `probe.py`: new `CertInfo` + `VerboseDetail` dataclasses; `Options.verbose`;
+  `Result.detail`; TTFB loop now accumulates until `\r\n\r\n` (unchanged TTFB
+  semantics — `t_first_byte` stamped on first `recv()`, not when headers complete);
+  captures resolved IP (from `getaddrinfo`), TLS version/cipher/bits
+  (from `sock.version()`/`sock.cipher()`), verified cert (from `getpeercert()`),
+  and all response headers
+- `cli.py`: verbose text block appended after timing rows in all four output
+  branches (single, aggregate, all-failed, mixed); `_VERBOSE_HEADERS` priority
+  list controls which headers appear in text mode; JSON `"verbose"` object
+  includes all parsed headers, full cert fields, TLS metadata; `"verbose"` key
+  omitted when flag is absent
+- 9 new hermetic probe tests, 15 new CLI tests covering verbose text and JSON
+  across success, connect-fail, and DNS-fail scenarios
+- 15 new integration tests for real TLS cert fields (CN, expiry, issuer),
+  IP format, TLS version string, header presence, and verbose text/JSON output
+- `python/configs/usage-latprobe.md`: runnable reference with real output for
+  all features including verbose and `--verbose --json`
+- `docs/usage/py-latprobe.md`: updated with `--verbose` flag and examples
+- Plan: `docs/plans/2026-07-01-12-55-py-latprobe-verbose.md`
+
+---
+
+## 2026-07-01 12:23 — Full `latprobe` Python package (Python, Step 3)
+
+- `python/latprobe/` package: full port of the Go CLI, runnable as `python -m latprobe`
+- `probe.py`: raw-socket HTTP measurement with `Options(timeout)` parameter; mirrors
+  `phases.py` technique; partial phases preserved on failure
+- `aggregate.py`: `summarize(List[Result]) -> Aggregate` with per-phase `PhaseStats(min_ms, avg_ms, max_ms)`
+- `duration.py`: parses Go-style duration strings (`10s`, `500ms`, `2m`, bare seconds)
+- `cli.py`: injectable `run(args, stdout, stderr) -> int`; argparse with injected streams
+  (`_Parser` subclass); `ThreadPoolExecutor` concurrency across URLs; four text-rendering
+  branches (single, aggregate, all-failed, mixed); JSON output; worst-exit-code accumulation
+- Exit codes: 0 ok, 1 usage, 2 dns, 3 connect, 4 timeout, 5 tls, 6 http≥400 (`--fail`)
+- `python/tests/test_probe.py`: 9 tests — success, 404, DNS fail, connect refused, TTFB
+  timeout, bad scheme, partial phase invariants; uses `http.server` + daemon threads
+- `python/tests/test_cli.py`: 23 tests — drives `cli.run()` in-process; covers usage
+  errors, single/aggregate text, failure exit codes, worst-code, `--fail`, JSON schema,
+  JSON ordering, JSON error grouping
+- Makefile `py-test`: added `PYTHONPATH=$(PY_DIR)`, removed `|| true`
+- User doc: `docs/usage/py-latprobe.md`
+
+---
+
 ## 2026-07-01 12:04 — Per-phase latency measurement (Python, Step 2)
 
 - `python/phases.py`: self-contained script; hand-drives raw sockets to time