Improve convert-to-trade security selection with search-first UX (#703)

* Enhance security handling logic:
- Prioritize user's country in sorting securities and country codes.
- Add comprehensive mapping for MIC codes to user-friendly exchange names.
- Revamp combobox to consistently pull from a provider when available.
- Improve handling of custom ticker and exchange input fields.

* Localize securities combobox display and exchange labels.

---------

Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>

app/models/security.rb

@@ -1,6 +1,132 @@
 class Security < ApplicationRecord
   include Provided
 
+  # ISO 10383 MIC codes mapped to user-friendly exchange names
+  # Source: https://www.iso20022.org/market-identifier-codes
+  EXCHANGE_NAMES = {
+    # United States - NASDAQ family (Operating MIC: XNAS)
+    "XNAS" => "NASDAQ",
+    "XNGS" => "NASDAQ",       # Global Select Market
+    "XNMS" => "NASDAQ",       # Global Market
+    "XNCM" => "NASDAQ",       # Capital Market
+    "XBOS" => "NASDAQ BX",
+    "XPSX" => "NASDAQ PSX",
+    "XNDQ" => "NASDAQ Options",
+
+    # United States - NYSE family (Operating MIC: XNYS)
+    "XNYS" => "NYSE",
+    "ARCX" => "NYSE Arca",
+    "XASE" => "NYSE American",  # Formerly AMEX
+    "XCHI" => "NYSE Chicago",
+    "XCIS" => "NYSE National",
+    "AMXO" => "NYSE American Options",
+    "ARCO" => "NYSE Arca Options",
+
+    # United States - OTC Markets (Operating MIC: OTCM)
+    "OTCM" => "OTC Markets",
+    "PINX" => "OTC Pink",
+    "OTCQ" => "OTCQX",
+    "OTCB" => "OTCQB",
+    "PSGM" => "OTC Grey",
+
+    # United States - Other
+    "XCBO" => "CBOE",
+    "XCME" => "CME",
+    "XCBT" => "CBOT",
+    "XNYM" => "NYMEX",
+    "BATS" => "CBOE BZX",
+    "EDGX" => "CBOE EDGX",
+    "IEXG" => "IEX",
+    "MEMX" => "MEMX",
+
+    # United Kingdom
+    "XLON" => "London Stock Exchange",
+    "XLME" => "London Metal Exchange",
+
+    # Germany
+    "XETR" => "Xetra",
+    "XFRA" => "Frankfurt",
+    "XSTU" => "Stuttgart",
+    "XMUN" => "Munich",
+    "XBER" => "Berlin",
+    "XHAM" => "Hamburg",
+    "XDUS" => "Düsseldorf",
+    "XHAN" => "Hannover",
+
+    # Euronext
+    "XPAR" => "Euronext Paris",
+    "XAMS" => "Euronext Amsterdam",
+    "XBRU" => "Euronext Brussels",
+    "XLIS" => "Euronext Lisbon",
+    "XDUB" => "Euronext Dublin",
+    "XOSL" => "Euronext Oslo",
+    "XMIL" => "Euronext Milan",
+
+    # Other Europe
+    "XSWX" => "SIX Swiss",
+    "XVTX" => "SIX Swiss",
+    "XMAD" => "BME Madrid",
+    "XWBO" => "Vienna",
+    "XCSE" => "Copenhagen",
+    "XHEL" => "Helsinki",
+    "XSTO" => "Stockholm",
+    "XICE" => "Iceland",
+    "XPRA" => "Prague",
+    "XWAR" => "Warsaw",
+    "XATH" => "Athens",
+    "XIST" => "Istanbul",
+
+    # Canada
+    "XTSE" => "Toronto",
+    "XTSX" => "TSX Venture",
+    "XCNQ" => "CSE",
+    "NEOE" => "NEO",
+
+    # Australia & New Zealand
+    "XASX" => "ASX",
+    "XNZE" => "NZX",
+
+    # Asia - Japan
+    "XTKS" => "Tokyo",
+    "XJPX" => "Japan Exchange",
+    "XOSE" => "Osaka",
+    "XNGO" => "Nagoya",
+    "XSAP" => "Sapporo",
+    "XFKA" => "Fukuoka",
+
+    # Asia - China
+    "XSHG" => "Shanghai",
+    "XSHE" => "Shenzhen",
+    "XHKG" => "Hong Kong",
+
+    # Asia - Other
+    "XKRX" => "Korea Exchange",
+    "XKOS" => "KOSDAQ",
+    "XTAI" => "Taiwan",
+    "XSES" => "Singapore",
+    "XBKK" => "Thailand",
+    "XIDX" => "Indonesia",
+    "XKLS" => "Malaysia",
+    "XPHS" => "Philippines",
+    "XBOM" => "BSE India",
+    "XNSE" => "NSE India",
+
+    # Latin America
+    "XMEX" => "Mexico",
+    "XBUE" => "Buenos Aires",
+    "XBOG" => "Colombia",
+    "XSGO" => "Santiago",
+    "BVMF" => "B3 Brazil",
+    "XLIM" => "Lima",
+
+    # Middle East & Africa
+    "XTAE" => "Tel Aviv",
+    "XDFM" => "Dubai",
+    "XADS" => "Abu Dhabi",
+    "XSAU" => "Saudi (Tadawul)",
+    "XJSE" => "Johannesburg"
+  }.freeze
+
   before_validation :upcase_symbols
 
   has_many :trades, dependent: :nullify, class_name: "Trade"
@@ -11,6 +137,16 @@ class Security < ApplicationRecord
 
   scope :online, -> { where(offline: false) }
 
+  # Returns user-friendly exchange name for a MIC code
+  def self.exchange_name_for(mic)
+    return nil if mic.blank?
+    EXCHANGE_NAMES[mic.upcase] || mic.upcase
+  end
+
+  def exchange_name
+    self.class.exchange_name_for(exchange_operating_mic)
+  end
+
   def current_price
     @current_price ||= find_or_fetch_price
     return nil if @current_price.nil?