refactor(internal): full idiomatic restructure with cobra CLI, typed structs, tool registry, and tests

[kilo-code-bot]

Summary

• Restructure from flat single-file layout to idiomatic Go package structure with cmd/, internal/ packages
• Replace hand-rolled flag parsing with cobra CLI for 20+ commands
• Introduce client.Client interface with context propagation, timeouts, and response size limits
• Add typed API structs (TriageResult, Issue, PullRequest, Label, etc.) replacing map[string]any
• Rewrite MCP server with declarative tool registry eliminating massive DRY violation
• Fix 33 code review findings (4 Critical, 6 High, 13 Medium, 7 Low, 3 Nitpick)
• Add unit + integration tests (28 Go files, ~40 test cases across 7 test files)

Bug Fixes

• [Critical] Unguarded type assertion panic in printTriageMarkdown — now uses typed structs
• [Critical] http.NewRequest error silently ignored — now checked in client/client.go
• [Critical] No HTTP client timeout — added 30s timeout via config.Config
• [Critical] json.Unmarshal error ignored in triage — now returns error

Security

• URL-encode all user-supplied --owner/--repo via url.PathEscape/url.QueryEscape
• Warn on stderr if GITEA_URL uses non-HTTPS scheme
• io.LimitReader with configurable max response size (default 10MB)

Architecture

cmd/gitea-robot/          # Cobra CLI entry point (7 files)
internal/config/          # Config struct with timeout validation
internal/client/          # HTTP client interface (Get/Post/Patch/Delete)
internal/cmdutil/         # Shared flag helpers (RequireOwnerRepo, ReadBody)
internal/gitea/           # Typed API operations (8 files)
internal/mcp/             # MCP server with tool registry (6 files)
internal/triage/          # Markdown formatting

Test Coverage

• internal/client/client_test.go — httptest mock server (GET/POST/PATCH/DELETE/timeout)
• internal/gitea/gitea_test.go — httptest integration for all API operations
• internal/triage/format_test.go — triage markdown output
• internal/mcp/registry_test.go — MCP tool registry, arg validation
• internal/mcp/server_test.go — JSON-RPC server integration
• internal/cmdutil/cmdutil_test.go — flag helpers

CI/CD

• Added go test -race ./... to both GitHub and Gitea CI workflows
• Added set -e to Gitea release upload step
• Added Windows builds to both release workflows
• Fixed .gitignore to not match cmd/gitea-robot/ directory