Ingest all camera angles, not a fixed four

[danielchalmers]

What & why

Tesla HW4/AI4 vehicles record two extra B-pillar cameras (left_pillar, right_pillar), and future firmware may add more. The filename parser already captured any suffix, but everything downstream looped a fixed four-camera list (CameraNames.All), so a fifth/sixth camera was silently dropped — discovered on disk, then thrown away.

This is P0 of the dynamic-camera work: ingest every camera and never crash. The extra angles are now parsed, kept, and have playback playlists built — surfacing them in the UI is a follow-up (P1).

Changes

• Build playlists for the cameras actually present in a clip instead of the fixed CameraNames.All (FfconcatMediaSourceBuilder). The front camera still drives the shared timeline.
• Canonicalize the legacy rear_view suffix to back at parse time (CamFile) so old and new clips share one vocabulary.
• Fix a latent whole-folder-drop crash (CamChunk): a duplicate camera suffix at one timestamp used to throw in ToDictionary, and because CamClip.TryMap swallows exceptions, the entire clip folder silently vanished from the library. Now keep-first + log.
• Add left_pillar/right_pillar to CameraNames.All.

Scope notes

• UI still shows four cameras — the intended P0 interim. A HW4 owner's pillar footage is now ingested and playlist-built, just not yet displayed.
• Front stays the timeline/required anchor. Generalizing to a "resolved primary" is deferred to P1, where the player pool changes too (zero practical gain now — front is universal on real Teslas).

Tests

235 pass, 0 failures (14 new; existing suite unchanged). New coverage:

• 6-camera clip builds pillar playlists; HW3 4-camera clip builds exactly four with no pillars (missing pillars ≠ corruption).
• Unknown suffix (front_bumper) still gets a playlist.
• Duplicate suffix keeps-first without dropping the folder; CamChunk.Map retains pillar/unknown cameras.
• rear_view canonicalizes to back at parse.

Verified against ehendrix23/tesla_dashcam: the six on-disk suffixes are front, back, left_repeater, right_repeater, left_pillar, right_pillar.