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_C/C_Errors.md

@@ -0,0 +1,69 @@
+---
+id: c-errors
+title: "C Errors"
+category: "Programming_Language"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["compile-time vs runtime errors", "use-after-free", "C 에러"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.86
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["c", "programming-language", "w3schools", "errors"]
+raw_sources: ["https://www.w3schools.com/c/c_errors.php"]
+applied_in: []
+github_commit: ""
+---
+
+# [[C Errors]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+The three runtime error examples (divide-by-zero, out-of-bounds array access, use-after-free) all share a common trait the source doesn't state explicitly but demonstrates through selection: NONE of them are caught by the compiler — all three compile cleanly and only misbehave when actually EXECUTED — meaning C's compile-time checking is fundamentally limited to syntax/type issues, while logic and memory-safety issues are entirely the programmer's responsibility to prevent at runtime. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **Compile-time errors** — prevent the program from compiling at all; e.g. missing semicolon, undeclared variable, mismatched types (assigning a string literal to an `int`). [S1]
+- **Runtime errors** — the program compiles successfully but crashes or misbehaves when RUN; e.g. division by zero, out-of-bounds array access, using memory after `free()`. [S1]
+- **Use-after-free** — reading `*ptr` after `free(ptr)` is explicitly labeled "undefined behavior," not a guaranteed crash — meaning it might appear to work sometimes, making it a particularly dangerous class of bug. [S1]
+- **Good habits** — always initialize variables, use meaningful names, keep indentation clean, keep functions short/focused, verify loop/condition behavior, and read error messages carefully (they often pinpoint the exact problem). [S1]
+
+## 📖 세부 내용 (Details)
+- Missing semicolon (compile-time): `int x = 5 printf("%d", x);` → `error: expected ',' or ';' before 'printf'`. [S1]
+- Type mismatch (compile-time): `int x = "Hello";` → `error: initialization makes integer from pointer without a cast`. [S1]
+- Use-after-free (runtime, undefined behavior): `int* ptr = malloc(sizeof(int)); *ptr = 10; free(ptr); printf("%d\n", *ptr); // accessing freed memory`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+- **해제된 메모리 접근은 "미정의 동작"**: free() 이후 포인터를 읽는 것이 항상 크래시로 이어지는 것이 아니라 "undefined behavior"로 명시되어, 우연히 정상 동작하는 것처럼 보일 수도 있어 더 위험하다는 점이 확인됨. [S1]
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — 컴파일 타임 에러 3종과 런타임 에러 3종을 나란히 대비시킨 것이 두 에러 범주의 근본적 차이를 이해하는 실전 학습 자료로 활용된다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+Using memory after it's been freed — compiles fine, but is undefined behavior at runtime (C):
+```c
+int* ptr = malloc(sizeof(int));
+*ptr = 10;
+free(ptr);
+printf("%d\n", *ptr); // Undefined behavior - accessing memory that was freed
+```
+
+## ✅ 검증 상태 및 신뢰도
+- **상태:** draft
+- **검증 단계:** conceptual
+- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
+- **신뢰 점수:** 0.86
+- **중복 검사 결과:** 신규 생성 (New discovery)
+
+## 🔗 지식 그래프 (Knowledge Graph)
+- **상위/루트:** [[C Tutorial]]
+- **관련 개념:** [[C Date Time]], [[C Memory Deallocate]], [[C Error Handling]]
+- **참조 맥락:** 에러 섹션 첫 챕터 — 에러 처리(Error Handling) 챕터로 이어짐.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — C Errors — https://www.w3schools.com/c/c_errors.php
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "C Errors" page (Astra wiki-curation, P-Reinforce v3.1 format).