Two more grammar gaps from the v0.3.0 sample run

1. SubName accepts any BSL keyword as the sub name, not just Identifier.
   'Процедура Выполнить()' is a real-world pattern — methods named after
   keywords appear in configuration code. Same root cause as the
   PropertyAccess/CallAccess keyword-after-dot fix, just in declaration
   position; reusing the existing dotIdentifier rule covers it cleanly.

2. constValue accepts String+ (one or more adjacent strings) instead of
   a single String. ANTLR's BSL grammar has 'string : (STRING |
   multilineString)+' for the same reason: code routinely concatenates
   string segments by juxtaposition — '"" "Выбрать" "Валюты.Код"' is
   one logical literal made of three tokens.

Sample-set numbers move from 84%/88% to 88%/88% (lsl/vsc). Remaining 8
degraded files are: 4 source-level errors (intentional *ParseError*
test inputs or real typos like 'Неопределенно' / 'Функция Пример3'
without parens), 3 comma-skipping in argument lists (documented
Limitation), 1 multi-line string edge case with adjacent tabs and
'""escape""' patterns inside a string concatenation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: nixel2007

src/bsl.grammar

@@ -96,7 +96,12 @@ FunctionDecl {
   EndFunction
 }
 
-SubName { Identifier }
+// Procedure/function names — same problem as PropertyAccess/CallAccess: a
+// method named after a BSL keyword (`Процедура Выполнить()` is a real,
+// observed pattern) globally specializes to the keyword term and SubName
+// would reject it. dotIdentifier already covers Identifier OR any BSL
+// keyword, so we reuse it here.
+SubName { dotIdentifier }
 
 paramList { Param (Comma Param)* }
 
@@ -310,11 +315,16 @@ lvalue { refHead accessChain }
 
 constValue {
   Number |
-  String |
+  String+ |
   Date |
   True | False | Undefined | Null
 }
 
+// ANTLR allows `string : (STRING | multilineString)+` — adjacent string
+// literals are implicitly concatenated. Real codebases use this to break a
+// long query across several `"…"` segments without writing `+` between
+// them; without `String+` we error out at the second String token.
+
 unaryConstValue {
   UnaryOp? constValue
 }