hygiene: Phase 5 — correct stale comments + name safe magic numbers

Fifth phase of the code-hygiene remediation, done per-file (18 files) via an
18-agent Workflow with strict guardrails. No consensus or security VALUES
changed (verified: pow/hush_utils/hush_bitcoind/net.h/crypter/stratum have
zero non-comment numeric changes); built clean, self-mined, verifychain=true.

Totals: 57 stale comments corrected, 46 user-facing branding fixes, 6
behavior-preserving named constants, 4 stratum warnings, 77 items deliberately
left (consensus/security values, copyright headers).

- Stale comments -> DragonX: corrected HUSH3/HUSH/Komodo/Equihash/Arrakis
  leftovers that misdescribed the active chain (pow AWT/lwma notes, txdb
  "Equihash solution" -> RandomX, wallet CLTV/overwinter/Sapling@1 notes,
  util datadir provenance, crypter's stale mapSproutSpendingKeys invariant).
  Replaced unprofessional/editorializing comments (profane TODOs, "developers
  are elite") with neutral technical notes, preserving the real design info.
- User-facing branding: dumpwallet header "created by Hush" -> "DragonX";
  RPC help text hushd/hush-cli/hushprivkey/hushaddress/Agama -> dragonx*;
  rebranded provably-dead "HUSH3" symbol-fallback literals to DRAGONX.
- Named constants (same values, non-consensus/non-security): addrman
  peer-selection factors (kChanceFactorGrowth/kChanceScale/deprioritize),
  sietch MIN_ZOUTS, an init notarization-DB cache size.
- Left the security macros (ECC/TFM_TIMING_RESISTANT=420, comment-clarified
  only), the consensus subsidy/commission literals + 128/129 TRANSITION
  (comment only), and copyright headers untouched.
- Added a prominent WARNING that the stratum server is Equihash-era and NOT
  updated for DragonX's RandomX PoW (flagged, not rewritten).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/hush_nSPV_fullnode.h

@@ -38,7 +38,8 @@ struct NSPV_ntzargs
 int32_t NSPV_notarization_find(struct NSPV_ntzargs *args,int32_t height,int32_t dir)
 {
     int32_t ntzheight = 0; uint256 hashBlock; CTransaction tx; Notarization nota; char *symbol; std::vector<uint8_t> opret;
-    symbol = (SMART_CHAIN_SYMBOL[0] == 0) ? (char *)"HUSH3" : SMART_CHAIN_SYMBOL;
+    // Notarization symbol; the empty-symbol fallback is dead on DragonX (SMART_CHAIN_SYMBOL is always "DRAGONX", never empty)
+    symbol = (SMART_CHAIN_SYMBOL[0] == 0) ? (char *)"DRAGONX" : SMART_CHAIN_SYMBOL;
     memset(args,0,sizeof(*args));
     if ( dir > 0 )
         height += 10;