docs(10_Wiki): Dev 폴더 누락분 반영 — Topic_Programming으로 통합

이전 재구성 작업에서 Dev/ 폴더가 누락되었던 것을 반영.

- Dev/Topic_Programming(중첩 폴더, 78개)은 Dev 자체 최상위 폴더들
  (Architecture/Conventions/Engineering_Intelligence 등)과 완전 중복이라 제거.
- Dev 최상위 엔지니어링 지식 폴더(Architecture/Conventions/Engineering_Intelligence/
  Failure_Library/Generalized_Principles/Language/Pattern_Catalog/Platform_Guides/
  Subsystems, 77개)는 이미 Topic_Programming/Topic_Programming에 더 최신 버전이
  존재해 중복 제거(고유 콘텐츠 1개는 예외 처리하여 이동 보존).
- Dev의 W3Schools 언어 튜토리얼 폴더(Topic_C/CPP/CSS/CSharp/HOWTO/HTML/Java/
  JavaScript/PHP/Python/SQL/W3CSS, 1201개)는 전부 Topic_Programming 하위로 이동.
- 에이전트 운영 상태(.astra/docs)는 그대로 유지, 콘텐츠 폴더만 정리.
- Topic_Programming 최종 문서 수: 2784 → 3985.

10_Wiki/Topic_Programming/Topic_PHP/PHP_Variables.md

@@ -0,0 +1,70 @@
+---
+id: php-variables
+title: "PHP Variables"
+category: "Programming_Language"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["PHP 변수"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.9
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["php", "programming", "w3schools", "variables"]
+raw_sources: ["https://www.w3schools.com/php/php_variables.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[PHP Variables]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+PHP has NO variable declaration command — a variable is created the instant you assign it a value (`$x = 5;`), unlike statically-declared languages; this is the source's explicit framing of what makes PHP "loosely typed" from the very first line of variable usage. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **`$` prefix** — every variable name starts with `$`. [S1]
+- **Naming rules** — starts with a letter or underscore (never a number); alphanumeric + underscore only; case-sensitive. [S1]
+- **No declaration keyword** — a variable springs into existence at first assignment. [S1]
+- **Loosely typed** — PHP infers the data type from the assigned value; no explicit type annotation needed. [S1]
+- **`var_dump()`** — reveals both the data type and value of a variable. [S1]
+- **Multiple assignment** — `$x = $y = $z = "Fruit";` assigns the same value to several variables in one statement. [S1]
+- **Supported data types** — string, int, float, bool, array, object, null, resource, mixed. [S1]
+
+## 📖 세부 내용 (Details)
+- Basic assignment: `$x = 5; $y = "John";`. [S1]
+- Output with interpolation: `$txt = "W3Schools.com"; echo "I love $txt!";` — equivalent to `echo 'I love ' . $txt . '!';`. [S1]
+- Type inspection: `var_dump(5); var_dump("John"); var_dump(3.14); var_dump(true); var_dump([2, 3, 56]); var_dump(NULL);`. [S1]
+- Multi-assignment: `$x = $y = $z = "Fruit";`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+소스에서 모순되는 정보는 발견되지 않음.
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — var_dump()로 변수의 실제 타입과 값을 확인하는 것이 디버깅의 표준 도구다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+Multi-variable assignment in one line (PHP):
+```php
+$x = $y = $z = "Fruit";
+```
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual
+- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
+- **신뢰 점수:** 0.90
+- **중복 검사 결과:** 신규 생성 (New discovery)
+
+## 🔗 지식 그래프 (Knowledge Graph)
+- **상위/루트:** [[PHP Tutorial]]
+- **관련 개념:** [[PHP Variables Scope]], [[PHP Echo Print]], [[PHP Data Types]]
+- **참조 맥락:** 변수 기초 문법 — 스코프(Scope)/데이터 타입 챕터로 확장.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — PHP Variables — https://www.w3schools.com/php/php_variables.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "PHP Variables" page (Astra wiki-curation, P-Reinforce v3.1 format).