feat: add analyze tool for project-scoped cop diagnostics

[Arthurvdv]

Summary

• Adds a native analyze MCP tool that wraps al_compile with onlyErrors=false, enableCodeAnalysis=true and no diagnostic cap, then enriches each diagnostic with the owning analyzer name and whether a native code fix exists.
• Adds CompileDiagnosticsParser — a pure, stateless parser for almcp's al_compile response JSON that handles camelCase/PascalCase, numeric/string severities, the SourceFile(path@line:col) location format (including paths with parentheses and @), and message warnings.
• Adds a multi-project CreateProxy overload to AlMcpFixture for integration tests that need diagnostics from more than one AL project.

What changed

• src/ALCops.Mcp/Models/AnalyzeResult.cs — record types for the tool's JSON output: AnalyzeDiagnostic, AnalyzeSummary, AnalyzeResult.
• src/ALCops.Mcp/Services/CompileDiagnosticsParser.cs — static parser: Parse (CallToolResult and string overloads), ParseLocation, ExtractWarnings, IsCompilerDiagnostic, Enrich, Filter, Sort, Build. No BC types, no I/O.
• src/ALCops.Mcp/Tools/AnalyzeTool.cs — the MCP tool endpoint. Resolves the proxy via IServiceProvider so it becomes {error:"ProxyUnavailable"} under --no-proxy instead of a schema leak. Parameters: filePath, folderPath, projectPath, severities, analyzers, ruleIds, limit.
• tests/ALCops.Mcp.Tests/CompileDiagnosticsParserTests.cs — 26 pure unit tests covering location parsing, JSON deserialization (camelCase, PascalCase, numeric severities, missing code, unknown properties), CallToolResult extraction (structured wins, non-JSON fallback, no-JSON throws), warning extraction, compiler-diagnostic detection, enrichment, filtering (file path, folder prefix, project+file AND, unlocated, severities, analyzers, ruleIds), sorting and build (truncation, summary, key order).
• tests/ALCops.Mcp.Tests/AnalyzeToolTests.cs — 3 no-almcp unit tests (ProxyUnavailable when no proxy, ProxyUnavailable when almcp unavailable, schema check), 7 [AlMcpFact] integration tests against a two-project workspace (project-scoped, default scope, explicit ProjB, filtered by rule+severity+project, limit truncation, Compiler analyzer filter, invalid limit).
• tests/ALCops.Mcp.Tests/AlMcpProxyTests.cs — added CreateProxy(CapturingLogger, IReadOnlyList<string>) overload for multi-project fixtures.
• AGENTS.md, README.md, src/ALCops.Mcp/README.md — updated tool count from four to five, added analyze to tool tables, documented analyze as the preferred verification call, noted the al_compile onlyErrors default.

Behaviour changes

• New tool analyze available when almcp is present (not under --no-proxy).
• No changes to existing tools or ForwardAsync.
• McpHost.cs is untouched; analyze is auto-discovered via WithToolsFromAssembly().

Test plan

• dotnet build --configuration Release — 0 warnings, 0 errors
• dotnet test --configuration Release — 216 passed, 0 failed, 0 skipped
• Parser unit tests (26) cover all parsing paths, edge cases and key ordering
• No-almcp unit tests verify ProxyUnavailable with message mentioning --no-proxy and "not available"
• Schema test confirms services and cancellationToken are hidden from the input schema
• Integration tests run against real almcp with two AL projects (ApplyFixProject + FixAllProject)
• Project-scoped results contain only diagnostics from the scoped project
• Filter by ruleId+severity+project returns only matching LC0020 hits, sorted by file
• limit: 1 produces truncated: true with totalCount > 1
• analyzers: ["Compiler"] returns only AL#### diagnostics
• Existing tests unchanged and still passing

Closes #31

Side observation (fixed in this PR)

ApplyFixThenCompileTests passed onlyErrors as a top-level al_compile argument, which almcp ignores; the flag lives inside the options object. The tests still worked because an absent options object also defaults to onlyErrors: false (and disables the diagnostics cap), not because warnings survive an errors-only filter. The tests now pass options: { onlyErrors: false } and the README/AGENTS.md wording names the options object.

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