re: the per-phase objectives, from the game's own text

TextIndex in sylpheed-formats::localization already indexes per-phase objective
text under S<NN>_P<n>_Objective_<i>, with hints and lose conditions alongside.
Querying it settles what the wave work spent many iterations circling, and a
disc test now pins it.

Stage 02 phase 1 is "Shoot down all invading enemy fighters while watching out
for attacks on the ACROPOLIS", losing if the ACROPOLIS is sunk. Phase 2 is
"Protect the Admiral's ship the CALIBAN until it has entered the safe zone",
losing if the CALIBAN is sunk. Phase 3 is "Destroy the interstellar cruise
missiles headed for Schlos Base", matching phase 3's roster of exactly nine
ISCMissile and SUBOBJ_013.

That explains the phase advances and shows they are not all the same kind. Phase
1 is a kill-all-marked-fighters gate -- fighters, not the turrets every run
killed almost exclusively. Phase 2 is positional and ends when the CALIBAN
reaches a safe zone, so "what advances a phase" never had a single answer.

It also closes a loop to the first session. The hints say red mission markers
[OB] indicate your targets, so REMAINING OB -- the HUD counter hunted in the
earliest iterations and located at 0xbdb59668 -- is the count of remaining
marked objective targets, which is phase-1 progress itself. The old reframing
that the counter is not a roster was right, and this names what it is. It is
also the correct signal to watch for an advance: not deployed, which only
changes once the next phase deploys, but REMAINING OB reaching zero, which is
the cause.

Method lesson recorded because the reflex will recur: localization.rs has had
objectives, hints and lose_conditions for some time, and several iterations were
spent reconstructing the same information by hand from SUBObjective strings and
the guide script. The reconstruction was not wasted -- it produced the IXUD
UTF-16BE and language\ prefix findings independently -- but the corpus should
have been searched before the disc was, and grep -rl TextIndex crates/ would
have saved the detour.

Minor discrepancy noted, not investigated: ixud.rs documents the string pool as
UTF-16BE and localization.rs as UTF-16LE.

docs/re/BACKLOG.md

@@ -560,6 +560,20 @@ search cannot find a *schedule*.
   the pilot (game-playing, uncertain); (2) accept the static answer (structure,
   rosters, routes, objective texts all decoded and cross-confirmed; only the
   *trigger* is inferred); (3) one 40+ min chained run betting against freezes.
+* ✅✅ **(2026-08-24) THE OBJECTIVES, FROM THE GAME'S OWN TEXT** — pinned by
+  `tests/phase_objectives_disc.rs`; `TextIndex::objectives(stage, phase)` already
+  existed. **S02 phase 1: "Shoot down all invading enemy fighters while watching
+  out for attacks on the ACROPOLIS"** (lose: ACROPOLIS sunk). **Phase 2: "Protect
+  the CALIBAN until it has entered the safe zone"** — *positional, not a kill
+  count*, so phase triggers are NOT all the same kind. **Phase 3: "Destroy the
+  interstellar cruise missiles headed for Schlos Base"** (matches the 9
+  `ISCMissile` + `SUBOBJ_013`). ✅ **`[OB]` = objective marker** — hints say *"Red
+  mission markers [OB] indicate your targets"*, so **`REMAINING OB` at
+  `0xbdb59668` is phase-1 progress** and is the right signal to watch, not
+  `deployed`. Closes a loop to the first session. 🔴 **Method lesson: the crate
+  already knew this** — several iterations reconstructed it the hard way;
+  `grep -rl TextIndex crates/` would have saved the detour. ❔ Minor: `ixud.rs`
+  says UTF-16BE, `localization.rs` says LE — one comment is wrong.
   🔴 `SYLPH_HZ=3` refuted as a lever: it gave the LOWEST frame rate (8/s) with the
   most kills, so pilot polling is not the throttle.
 * ~~🚧 BLOCKER: t=210/240 unreachable in one turn~~ — **superseded, see above**;