Add in-process unit tests and 100% coverage config

[rjmurillo]

What

Adds direct unit tests plus coverage config:

• tests/test_ditto_unit.py: imports ditto and exercises every branch:
  redaction, log-shape parsing for Codex, Claude, and Copilot, verbatim
  dedupe, session labelling, chunking, stats, the profile card (terminal and
  HTML rendering, browser open, fallbacks), all install targets, and main()
  dispatch including --card.
• .coveragerc: branch coverage on the ditto module.
• .gitignore: ignore .coverage and htmlcov/.

Reaches 100% statement and branch coverage of ditto.py (377 statements, 152
branches, 0 missed), 75 tests.

Why

The existing tests drive the CLI end to end through subprocess, so they never
import ditto and do not measure its own lines. These do, and they lock the
behavior of the card renderer and the dedupe path against regressions.

Run

python -m coverage run -m unittest discover -s tests && python -m coverage report

The plain CI command also passes:

python -m unittest discover -s tests -v

[ohad6k]

saw this one too — it's marked draft so i'll wait for you to take it out of draft. heads up that main just moved (card feature + your copilot source merged), so it'll need a rebase. the in-process test approach looks right.

[rjmurillo]

rebased and added test cases for the new code so things are at 100% coverage; ready for review

[ohad6k]

Really appreciate this. 75 tests and full-branch coverage is exactly what I want sitting under the rewrite that's coming.

One thing before I merge: it's green on your CI but red on Windows for me. test_all_targets_and_unknown asserts the install paths with forward slashes:

ditto.install_destination("claude", "/repo", "/home").endswith("/.claude/skills/you/SKILL.md")

On Windows that returns \home\.claude\skills\you\SKILL.md, so the endswith fails. The product path is correct, the assertion just isn't cross-platform. Normalizing the separator before the check fixes it:

dest = ditto.install_destination("claude", "/repo", "/home").replace(os.sep, "/")
self.assertTrue(dest.endswith("/.claude/skills/you/SKILL.md"))

Ditto ships on Windows (Hebrew paths and all), so I want the suite green there too before it goes in. Fix that and I'll merge.

Heads up: there's a bigger ditto.py rewrite in flight (bounded mining, stable segments, caching), so some of these tests will need to move with it. Having them here makes that safer, not wasted.

If you want to go back and forth on it, come hang in the Discord: https://discord.gg/VNnMq2U5r

[rjmurillo]

I pulled this back into draft. I won't be near a Windows machine until next week and I can wait for the in flight to land and get the coverage needed

[ohad6k]

Perfect, no rush at all. The rewrite should land before you're back at a Windows machine, and your suite is going to make merging it a lot safer. Ping me when you take it out of draft.