feat: 明确音频优先级，优化发车音频触发时机

- 到达与发车最高优先级(3)，其次是进站预告(2)，然后是延误警告(1)，最低为背景音乐(0)

- 将发车音乐的触发时机从固定时间改为动态计算（音频时长+1.5秒补偿），确保音频结束时列车刚好发车

- 拆分 handleTrainApproaching 与 handleTrainAlert 逻辑，解耦进站与延误的优先级

- 版本号提升至 v1.0.59

test_keywords.lua

@@ -0,0 +1,49 @@
+function getKeywords(text)
+    if not text then return {} end
+    local s = tostring(text):lower()
+    
+    local keywords = {}
+    
+    for code in s:gmatch("[%a%d]+%-[%a%d]+") do
+        keywords[code] = true
+    end
+    for code in s:gmatch("%a+%d+") do
+        keywords[code] = true
+    end
+    
+    for zh in s:gmatch("[\128-\255]+") do
+        local cleanZh = zh:gsub("站台", ""):gsub("轨道", ""):gsub("号", ""):gsub("线", "")
+        if cleanZh and cleanZh ~= "" then
+            keywords[cleanZh] = true
+        end
+    end
+    
+    local list = {}
+    for k, _ in pairs(keywords) do
+        table.insert(list, k)
+    end
+    return list
+end
+
+local function test(a, b)
+    local k1 = getKeywords(a)
+    local k2 = getKeywords(b)
+    local match = false
+    for _, w1 in ipairs(k1) do
+        for _, w2 in ipairs(k2) do
+            if w1 == w2 or w1:find(w2, 1, true) or w2:find(w1, 1, true) then
+                match = true
+                break
+            end
+        end
+    end
+    print(a .. " vs " .. b .. " -> " .. tostring(match))
+    print("  K1: " .. table.concat(k1, ", "))
+    print("  K2: " .. table.concat(k2, ", "))
+end
+
+test("CE-03 (桃园)", "桃园")
+test("CE-04", "CE-04 [西门]")
+test("CRH-01", "CRH-01 南山线")
+test("南山线", "南山")
+test("???", "Unknown")