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/txdb.cpp

@@ -285,8 +285,9 @@ bool CBlockTreeDB::WriteBatchSync(const std::vector<std::pair<int, const CBlockF
         std::pair<char, uint256> key = make_pair(DB_BLOCK_INDEX, it->GetBlockHash());
         try {
             CDiskBlockIndex dbindex {it, [this, &key]() {
-                // It can happen that the index entry is written, then the Equihash solution is cleared from memory,
+                // It can happen that the index entry is written, then the solution is cleared from memory,
                 // then the index entry is rewritten. In that case we must read the solution from the old entry.
+                // (GetSolution() returns DragonX's RandomX solution.)
                 CDiskBlockIndex dbindex_old;
                 if (!Read(key, dbindex_old)) {
                     LogPrintf("%s: Failed to read index entry", __func__);
@@ -698,7 +699,7 @@ bool CBlockTreeDB::LoadBlockIndexGuts()
                 pindexNew->nTime                  = diskindex.nTime;
                 pindexNew->nBits                  = diskindex.nBits;
                 pindexNew->nNonce                 = diskindex.nNonce;
-                // the Equihash solution will be loaded lazily from the dbindex entry
+                // the solution (DragonX RandomX solution) will be loaded lazily from the dbindex entry
                 // pindexNew->nSolution              = diskindex.nSolution;
                 pindexNew->nStatus                = diskindex.nStatus;
                 pindexNew->nCachedBranchId        = diskindex.nCachedBranchId;