docs: progression CONTEXT, ADRs 0001-0004, phase A plan

ignore .idea/ .superpowers/ bin/ obj/; drop 3 identical csproj backups

docs/adr/0003-only-first-clear-commits.md

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+# Only a First Clear commits an Attempt
+
+The game is moving from a purely sequential campaign to one where completionists can select and replay levels
+they have already beaten. Coins and skills bank only on a **First Clear** — the first completion of a Level
+within a Playthrough — while a **Replay** records Best Time, achievements and statistics to the Profile and
+discards the Attempt. We chose this over committing on every completion because grinding the easiest level would
+otherwise be the optimal way to buy every skill.
+
+## Consequences
+
+- A Replay must never advance campaign position. Sharing one code path between First Clear and Replay without an
+  explicit branch is the obvious way to reintroduce this bug.
+- `ClearedLevels` answers "is this a First Clear?" for free, since it already deduplicates.
+- Coins found during a Replay are lost on completion, not just on death. This is intentional and worth surfacing
+  in the UI.