fix(emit): disclose min_minutes-filtered frames in markdown

[Sarcastic-Soul]

Fixes #54

The gap

When min_minutes drops short frames, build_frames records how many on the document. Two of the three emitters pass that on. Markdown doesn't.

Same document, omitted_below_min = 1:

Emitter	Output
to_json	"omitted": {"below_min_minutes": 1, "min_minutes": 15.0}
context_block	(+1 brief frames under 15.0 min omitted)
to_markdown	nothing

So the markdown table presents a filtered day as the whole day.

Why it's worth a patch

-f md is a documented CLI format, and --min-minutes defaults to 0.5, not 0 — so aframes today -f md, the plain invocation, is already filtering. A reader has no way to tell that frames were removed or how many.

It's also the one place the codebase truncates without saying so. The same disclosure appears everywhere else, and communications.py states the intent outright:

omitted_titles: int = 0   # distinct titles beyond max_titles (disclosed, never silent)

The change

to_markdown already ends with a footer for away gaps:

if cov.get("gaps"):
    lines.append("")
    ...
    lines.append(f"**Away:** {gaps}")

This adds a matching one from the omitted block the document already produces:

**Omitted:** 1 frames under 15.0 min

Bold-label footer, same shape as **Away:**, appended only when something was actually dropped. No new state — it reads the dict to_dict() already builds.

Tests

Two in tests/test_frames_emit.py:

• test_every_emitter_discloses_frames_dropped_by_min_minutes — asserts all three emitters disclose the same count from one document, so the three can't drift apart again. Fails on main on the markdown assertion.
• test_unfiltered_markdown_has_no_omitted_footer — nothing dropped, no footer. Guards against a footer that always fires.

The fixture's frames run 14.0 / 19.7 / 24.0 min, so the test uses a 15 min floor: drops exactly one and still leaves a populated table to disclose against. (A 5 min floor drops nothing here — worth knowing, since test_min_minutes_filter asserts only <= and so passes either way.)

Full suite: 109 passed (107 before, +2).

Note on placement

The new tests are inserted mid-file rather than appended, so they don't collide with #40, which appends to the end of this same file. The two should merge cleanly in either order.