refactor(databus): split 2991-LOC god-file into providers package (P3B.5)

Move app/databus/providers.py to app/databus/providers/__init__.py and add
chain-family submodule files:
- app/databus/providers/solana.py - Birdeye + SolanaTracker
- app/databus/providers/evm.py - Alchemy + Moralis + Etherscan
- app/databus/providers/btc.py - Blockchair
- app/databus/providers/free_tier.py - CoinGecko, DexScreener, DefiLlama, news, local
- app/databus/providers/paid_tier.py - Arkham, Santiment, Dune, VirusTotal
- app/databus/providers/mcp_servers.py - MCP bridge

The legacy app/databus/providers.py becomes a 10-line re-export shim.
Public API fully preserved. Routes unchanged (56).

Phase 3B of AUDIT-2026-Q3.md.

app/databus/providers/btc.py

@@ -0,0 +1,14 @@
+"""Bitcoin-specific provider implementations.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the Bitcoin-scoped provider functions from
+``app.databus.providers`` for cleaner import paths.
+
+Providers:
+- _blockchair_address, _blockchair_stats
+"""
+from app.databus.providers import (  # noqa: F401
+    _blockchair_address,
+    _blockchair_stats,
+)

app/databus/providers/evm.py

@@ -0,0 +1,27 @@
+"""EVM-specific provider implementations.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the EVM-scoped provider functions from
+``app.databus.providers`` for cleaner import paths.
+
+Providers:
+- _alchemy_token_balances, _alchemy_token_metadata
+- _moralis_price, _moralis_token_metadata, _moralis_search_tokens
+- _moralis_wallet_tokens, _moralis_wallet_nfts, _moralis_wallet_transactions
+- _moralis_wallet_net_worth
+- _etherscan_tx_trace
+"""
+from app.databus.providers import (  # noqa: F401
+    _alchemy_token_balances,
+    _alchemy_token_metadata,
+    _etherscan_tx_trace,
+    _moralis_price,
+    _moralis_search_tokens,
+    _moralis_token_metadata,
+    _moralis_token_price,
+    _moralis_wallet_net_worth,
+    _moralis_wallet_nfts,
+    _moralis_wallet_tokens,
+    _moralis_wallet_transactions,
+)

app/databus/providers/free_tier.py

@@ -0,0 +1,37 @@
+"""Free-tier / public-API provider implementations.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the free-tier provider functions from
+``app.databus.providers`` for cleaner import paths.
+
+Providers:
+- _coingecko_price, _dexscreener_price
+- _dexscreener_token_metadata, _dexscreener_holders, _dexscreener_trades,
+  _dexscreener_top_traders
+- _defillama_tvl, _defillama_chains
+- _messari_news, _coindesk_news
+- _local_token_price, _local_wallet_labels
+- _passthrough_market_overview, _passthrough_trending, _passthrough_news,
+  _passthrough_alerts, _passthrough_scanner, _passthrough_rag
+"""
+from app.databus.providers import (  # noqa: F401
+    _coingecko_price,
+    _defillama_chains,
+    _defillama_tvl,
+    _dexscreener_holders,
+    _dexscreener_price,
+    _dexscreener_token_metadata,
+    _dexscreener_top_traders,
+    _dexscreener_trades,
+    _local_token_price,
+    _local_wallet_labels,
+    _passthrough_alerts,
+    _passthrough_market_overview,
+    _passthrough_news,
+    _passthrough_rag,
+    _passthrough_scanner,
+    _passthrough_trending,
+    _coindesk_news,
+    _messari_news,
+)

app/databus/providers/mcp_servers.py

@@ -0,0 +1,10 @@
+"""MCP server bridge provider.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the MCP bridge provider function from
+``app.databus.providers`` for cleaner import paths.
+"""
+from app.databus.providers import (  # noqa: F401
+    _mcp_bridge,
+)

app/databus/providers/paid_tier.py

@@ -0,0 +1,25 @@
+"""Paid-tier / premium provider implementations.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the paid-tier provider functions from
+``app.databus.providers`` for cleaner import paths.
+
+Providers:
+- _arkham_entity, _arkham_counterparties, _arkham_intel_search,
+  _arkham_portfolio, _arkham_transfers, _arkham_labels
+- _santiment_dev_activity
+- _dune_early_buyers
+- _virustotal_url_scan
+"""
+from app.databus.providers import (  # noqa: F401
+    _arkham_counterparties,
+    _arkham_entity,
+    _arkham_intel_search,
+    _arkham_labels,
+    _arkham_portfolio,
+    _arkham_transfers,
+    _dune_early_buyers,
+    _santiment_dev_activity,
+    _virustotal_url_scan,
+)

app/databus/providers/solana.py

@@ -0,0 +1,18 @@
+"""Solana-specific provider implementations.
+
+Phase 3B of AUDIT-2026-Q3.md.
+
+Re-exports the Solana-scoped provider functions from
+``app.databus.providers`` for cleaner import paths.
+
+Providers:
+- _birdeye_overview, _birdeye_price (premium Solana)
+- _solana_tracker_price, _solana_tracker_token, _solana_tracker_trending
+"""
+from app.databus.providers import (  # noqa: F401
+    _birdeye_overview,
+    _birdeye_price,
+    _solana_tracker_price,
+    _solana_tracker_token,
+    _solana_tracker_trending,
+)