docs(idl): vendor upstream pump.fun IDLs for reference

Snapshot of pump-fun/pump-public-docs @ 7de0b95 (2026-04-23) under
idl/upstream/ — pump.json, pump_amm.json, pump_fees.json and their .ts
counterparts. Used for local diffing against the IDLs the bot loads from
idl/; not imported at runtime. README links to the new directory.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

idl/upstream/SOURCE.md

@@ -0,0 +1,20 @@
+# Upstream pump.fun IDLs
+
+Source: https://github.com/pump-fun/pump-public-docs
+
+Snapshot commit: `7de0b959fa2bdab379a2f75f5433d3de1e35d229` (2026-04-23)
+
+Files:
+- `pump.json` / `pump.ts` — pump.fun bonding curve program
+- `pump_amm.json` / `pump_amm.ts` — pump-swap (PumpAMM) program
+- `pump_fees.json` / `pump_fees.ts` — pump fees program
+
+Kept here verbatim for reference and diffing against the IDLs the bot actually loads from `idl/`. Do not import these directly from runtime code.
+
+To refresh:
+
+```bash
+git clone --depth 1 https://github.com/pump-fun/pump-public-docs.git /tmp/pump-public-docs
+cp /tmp/pump-public-docs/idl/{pump,pump_amm,pump_fees}.{json,ts} idl/upstream/
+# update commit hash above
+```