feat: IDE支持 — workspace拆分、LSP服务器、VS Code扩展

**Workspace 拆分**
- aster-core: 纯库，zero-dependency，包含 lexer/parser/ast/interpreter/error/analysis
- aster: REPL 二进制，薄封装 aster-core
- aster-lsp: LSP 语言服务器

**VS Code 扩展 (vscode-ext/)**
- TextMate 语法高亮 (.ast 文件)
- 语言配置 (注释切换、括号配对、自动缩进)
- LSP 客户端 (extension.js)

**LSP 服务端功能**
- Diagnostics: 实时显示 lex/parse 错误红色波浪线
- Completion: 关键字 + 内置函数 + 用户定义符号补全
- Hover: 悬停显示变量/函数信息
- Signature Help: 函数参数提示
- Goto Definition: Ctrl+Click 跳转到声明处
- Find References: 查找所有引用位置
- Rename: F2 重命名符号

**新增 analysis 模块**
- collect_symbols: AST 遍历收集符号
- find_declaration/find_all_references: Token 扫描定位声明和引用

vscode-ext/syntaxes/aster.tmLanguage.json

@@ -0,0 +1,156 @@
+{
+    "$schema": "https://raw.githubusercontent.com/martinring/tmlanguage/master/tmlanguage.json",
+    "name": "Aster",
+    "scopeName": "source.aster",
+    "fileTypes": ["ast"],
+    "patterns": [
+        { "include": "#comments" },
+        { "include": "#strings" },
+        { "include": "#numbers" },
+        { "include": "#function-declaration" },
+        { "include": "#keywords" },
+        { "include": "#constants" },
+        { "include": "#builtins" },
+        { "include": "#operators" },
+        { "include": "#punctuation" },
+        { "include": "#identifiers" }
+    ],
+    "repository": {
+        "comments": {
+            "patterns": [
+                {
+                    "name": "comment.block.aster",
+                    "begin": "/\\*",
+                    "end": "\\*/",
+                    "patterns": [
+                        {
+                            "name": "comment.block.aster",
+                            "match": "."
+                        }
+                    ]
+                },
+                {
+                    "name": "comment.line.double-slash.aster",
+                    "match": "//.*$"
+                }
+            ]
+        },
+        "strings": {
+            "patterns": [
+                {
+                    "name": "string.quoted.double.aster",
+                    "begin": "\"",
+                    "end": "\"",
+                    "patterns": [
+                        {
+                            "name": "constant.character.escape.aster",
+                            "match": "\\\\[ntr\"\\\\]"
+                        }
+                    ]
+                },
+                {
+                    "name": "string.quoted.single.aster",
+                    "begin": "'",
+                    "end": "'",
+                    "patterns": [
+                        {
+                            "name": "constant.character.escape.aster",
+                            "match": "\\\\[ntr'\\\\]"
+                        }
+                    ]
+                }
+            ]
+        },
+        "numbers": {
+            "patterns": [
+                {
+                    "name": "constant.numeric.float.aster",
+                    "match": "\\b\\d+\\.\\d+\\b"
+                },
+                {
+                    "name": "constant.numeric.integer.aster",
+                    "match": "\\b\\d+\\b"
+                }
+            ]
+        },
+        "function-declaration": {
+            "match": "\\b(fn)\\s+([a-zA-Z_][a-zA-Z0-9_]*)",
+            "captures": {
+                "1": { "name": "keyword.control.aster" },
+                "2": { "name": "entity.name.function.aster" }
+            }
+        },
+        "keywords": {
+            "patterns": [
+                {
+                    "name": "keyword.control.aster",
+                    "match": "\\b(let|const|fn|if|else|while|for|in|break|continue|return)\\b"
+                }
+            ]
+        },
+        "constants": {
+            "match": "\\b(true|false|nil)\\b",
+            "name": "constant.language.aster"
+        },
+        "builtins": {
+            "match": "\\b(print|input|clock|len|typeof|push|pop|split|trim|substring|replace|contains|upper|lower|starts_with|ends_with|require)\\b",
+            "name": "support.function.builtin.aster"
+        },
+        "operators": {
+            "patterns": [
+                {
+                    "name": "keyword.operator.assignment.compound.aster",
+                    "match": "\\+=|-=|\\*=|/=|%="
+                },
+                {
+                    "name": "keyword.operator.logical.aster",
+                    "match": "&&|\\|\\||!"
+                },
+                {
+                    "name": "keyword.operator.comparison.aster",
+                    "match": "==|!=|<=|>="
+                },
+                {
+                    "name": "keyword.operator.assignment.aster",
+                    "match": "="
+                },
+                {
+                    "name": "keyword.operator.arithmetic.aster",
+                    "match": "[+\\-*/%]"
+                },
+                {
+                    "name": "keyword.operator.comparison.aster",
+                    "match": "<|>"
+                }
+            ]
+        },
+        "punctuation": {
+            "patterns": [
+                {
+                    "name": "punctuation.section.scope.aster",
+                    "match": "[{}]"
+                },
+                {
+                    "name": "punctuation.section.brackets.aster",
+                    "match": "[\\[\\]]"
+                },
+                {
+                    "name": "punctuation.section.parens.aster",
+                    "match": "[\\(\\)]"
+                },
+                {
+                    "name": "punctuation.separator.aster",
+                    "match": "[,;:\\.]"
+                },
+                {
+                    "name": "keyword.operator.ternary.question.aster",
+                    "match": "\\?"
+                }
+            ]
+        },
+        "identifiers": {
+            "match": "[a-zA-Z_][a-zA-Z0-9_]*",
+            "name": "variable.other.aster"
+        }
+    }
+}