feature: utility practice reliability, focus the lineup you load, small crosshair up close, clear/rethrow/bots/flash

[lukepolo]

Changes

Aim crosshair up close (SwiftlyS2 and CSS)

• The reticle size had a 9-unit floor. Facing a wall a few units away, it filled the screen and you couldn't find the aim point inside it.
• It now scales with distance all the way down, so it stays about 2.5° on screen at any range. The beam width and centre dot shrink with it.
• From about 200 units out it looks the same as before.
• The lineup name stays above the crosshair, sized the same way.
• The CSS port's aim ring scales the same way and gets a centre dot.

Text removed

• Removed the utility-type label over the landing spot.
• Removed the CSS port's "AIM" label.
• Removed the CSS port's "STAND / name" label on the ground. The lineup name now shows at the aim ring instead.

Focus the lineup you load (SwiftlyS2)

• Loading a lineup (website, .load / .next / .prev, HUD, solve, playbook) hides every other library marker for that player only, using ShouldBlockTransmitEntity.
• .all shows the full library again and keeps the lineup loaded. .clear, .reload, deleting the lineup, starting a drill or execute, disconnecting, a map change or a hot reload also bring it back.
• While a drill or execute runs, nothing is hidden.

Clear, rethrow, bots and flash (from #179)

• .clear holds until you ask for something again, and it also removes smokes, fires and grenades in the world.
• The ping key clears thrown utility.
• .rethrow throws the loaded lineup, or your last throw if nothing is loaded, from where it was thrown, without moving you.
• Bots that died or were added mid-round are respawned onto their spots.
• Flash feedback covers players as well as bots.

Reliability: markers disappearing, reloads, 2+ players (SwiftlyS2; one commit per fix)

• bb286b7 Shared layer for everyone:
  • The shared marker layer is built from every connected player's library, merged by client_id. The 150-lineup cap is shared round-robin between players.
  • Each entity remembers which lineup(s) it stands for, and each player is sent only theirs. Private lineups are no longer shown to the room.
  • Before, the library only redrew for a solo player, and .load / .save drew the caller's private library for everyone.
  • The layer redraws on every landed fetch, after .delete, and after a disconnect.
• e7cbfbf Round restart:
  • Markers and selections are redrawn after a round restart, warmup end or mp_restartgame.
  • Stale entity handles are now dropped instead of despawned. A recycled address reads as valid, so despawning a stale handle could have deleted an unrelated new entity. The same hazard existed on map load and is fixed there too.
• 85b895e Caller-only commands: .clear, .crosshair and .reload touch only the caller's own markers. .clear hides the library from the caller alone.
• 32b9a67 Fetch vs. save race: a library fetch that left before a save or delete no longer undoes it. Local changes are merged over the panel's answer until the panel agrees.
• 1edfd8d Upload retries: the retry queue drains every 30s while anything is queued, plus one bounded try on unload.
• c8702fe Hot reload:
  • The RoundStart hook is unhooked on unload.
  • A torn-down guard stops fetch answers, trajectory continuations and scheduled callbacks from a previous instance from drawing or teleporting.
• 97f9ad6 Same-map changelevel: changelevel onto the same map reloads everyone's library.
• 09a8314 .next / .prev position: your place is kept when your library refreshes.
• eba99ef Archived lineups: a lineup archived on the website is dropped from whoever has it loaded or focused, with a chat line telling them.
• 38640cf CSS port: gets the fetch merge and the retry drain. The other fixes don't apply there, because it has no shared layer, library drain or map flag.

Testing

Not compiled: there was no .NET SDK in the environment these were written in. The SwiftlyS2 API calls were checked by hand against its source. Needs a build plus an in-game pass:

1. Solo: .load, then mp_restartgame 1. Markers and the crosshair come back within about a second. Same after warmup ends.
2. Two players, A with private lineups and B without:
   • B sees only public lineups.
   • A .saves: the new marker shows for A only.
   • Make a lineup public on the website and push a refresh: B sees it.
3. A runs .clear: markers vanish for A only. A .loads: they come back.
4. A runs .crosshair and .reload: B's markers don't blink.
5. B disconnects: B's private lineups leave the layer.
6. .save then immediately a website push: the new lineup survives. .delete then a refresh: it stays gone.
7. Block the panel, .save, unblock: the save posts within about 30s. Hot reload with something queued: the log shows a flush or a warning.
8. Hot reload mid-map with 2 players: no duplicate or orphan markers, libraries come back, grenade models still render.
9. changelevel <same map>: libraries reload.
10. .next a few times, push a refresh, .next again: it continues where you were.
11. Archive your loaded lineup on the website, then refresh: you get the chat line and the library reappears.
12. Crosshair and focus: face a wall with a short lineup (crosshair and name stay small), no text above smokes, .all restores the library.
13. Clear, rethrow, bots and flash: .clear with live smokes, the ping key, .rethrow with and without a loaded lineup, .bot twice mid-round, flash timings in chat.
14. CSS: repeat checks 6 and 7.

Things to watch

• Visibility is re-applied to every player on each .load / .next (entities × players native calls). Watch tick time on a busy map.
• .spawns rings are forgotten on a round restart; run .spawns again.
• Grenade models after a first-ever mid-map load may not render, because there's no way to precache mid-map. A hot reload should keep the models the previous instance precached.