Remove lexy dependency, replace with hand-written tokenizer and Pratt parser (#1099)

* conditionally use from_char when available

* lexy removed

* Add hand-written tokenizer for scripting language

Implement BT::Scripting::tokenize() to replace the lexy-based tokenizer
that was removed. Handles all token types: identifiers (with @ prefix for
root blackboard vars), numbers (int/hex/real/exponent), single-quoted
strings, two-char operators, and single-char operators/delimiters.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix clang-tidy warnings in script parser and tokenizer

- Add explicit != 0 for implicit int->bool conversions from ctype
  functions (readability-implicit-bool-conversion)
- Value-initialize op variables in switch statements
  (cppcoreguidelines-init-variables)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Address SonarCloud warnings in script parser and tokenizer

Tokenizer:
- Extract scanHexNumber(), scanDecimalNumber(), matchTwoCharOp(),
  matchSingleCharOp() to reduce cognitive complexity of tokenize()
- Use init-statement in if for identifier text variable (S6004)

Parser:
- Replace std::runtime_error with RuntimeError (S112)
- Remove redundant lambda return type (S3574)
- Catch RuntimeError instead of std::exception (S1181)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add unit tests for tokenizer and parser edge cases

New test cases:
- TokenizerEdgeCases: unterminated strings, hex errors (0x, 0xG),
  exponent errors (3e, 3e+), DotDot with numbers, empty/whitespace scripts
- ChainedComparisons: 1<2<3, 3>2>1, mixed chains, chained equality
- OperatorPrecedence: bitwise vs logical, parenthesized subexpressions
- UnaryOperators: !, !!, ~, unary minus in expressions
- TernaryExpressions: basic, with subexpressions, comparison conditions
- MultipleStatements: extra semicolons, return value of last expression

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix test and coverage script

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: facontidavide

.github/workflows/ros2-rolling.yaml

@@ -19,4 +19,4 @@ jobs:
       - uses: 'ros-industrial/industrial_ci@master'
         env: ${{matrix.env}}
         with:
-            package-name: plotjuggler
+            package-name: behaviortree_cpp

.github/workflows/ros2.yaml

@@ -20,4 +20,4 @@ jobs:
       - uses: 'ros-industrial/industrial_ci@master'
         env: ${{matrix.env}}
         with:
-            package-name: plotjuggler
+            package-name: behaviortree_cpp

.gitignore

@@ -24,6 +24,9 @@ tags
 /llvm.sh
 t11_groot_howto.btlog
 minitrace.json
+
+TODO.md
 /.worktrees/*
 /docs/plans/*
 /coverage_report/*
+/coverage.info