dotnet
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diff --git a/‎.github/docs/state-machine.md‎
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diff --git a/‎.github/instructions/NoBloat.instructions.md‎
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diff --git a/‎.github/skills/fsharp-diagnostics/SKILL.md‎
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@@ -48,6 +48,8 @@ Before submitting: `./build.sh -c Release --testcoreclr`
 .fs: implementation
 .fsi: declarations, API docs, context comments
 
+Abbreviations (`ad`, `cenv`, `m`, `tcref`, `eenv`, `cgbuf`, `ncenv`, `tau`, …): see `docs/coding-standards.md` for the canonical glossary before guessing what a short identifier means.
+
 ## Rules
 
 Public API change → update .fsi
 
@@ -134,17 +134,24 @@ stateDiagram-v2
     [*] --> ScanQueue: ⏰ labelops-pr-security-scan (1h)
 
     state "Per-PR Classification" as ScanLoop {
-        ScanQueue --> ReadRules: 🤖 security-scan reads repo rules
-        ReadRules --> CheckDraft: 🤖 security-scan checks isDraft
+        ScanQueue --> ReadRules: 🤖 security-scan reads repo rules + memory
+        ReadRules --> CheckDate: 🤖 security-scan paginates PRs (newest first)
+
+        state datecheck <<choice>>
+        CheckDate --> datecheck
+        datecheck --> SkipOld: PR before date cutoff
+        datecheck --> CheckDraft: PR within scan window
+
+        SkipOld --> [*]: skip
 
         state draftcheck <<choice>>
-        CheckDraft --> draftcheck
+        CheckDraft --> draftcheck: 🤖 security-scan checks isDraft
         draftcheck --> SkipDraft: draft PR
         draftcheck --> CheckMemory: non-draft PR
 
         SkipDraft --> [*]: skip
 
-        CheckMemory --> CheckMemory2: 🤖 security-scan reads state.json
+        CheckMemory --> CheckMemory2: 🤖 security-scan checks state.json sha
 
         state memcheck <<choice>>
         CheckMemory2 --> memcheck
@@ -255,7 +262,7 @@ stateDiagram-v2
 aw-auto-update.md: da8c5e340a43d73616e3a0203c7e56de9ca4b82ee78b1902afe466a49a08bc17
 labelops-flake-fix.md: 7dca5b8faa60f947204f8925c6238fbecf42aa8cbf3144a166120501b0eef1e4
 labelops-pr-maintenance.md: 59ba52fc625e0b9112c31864e92154cdf09acf0bc0f2b167aa30a0d76baa898f
-labelops-pr-security-scan.md: 675430850eaf8edaa86b4d26c9d381ac48e13536469f17748e7104f6e75937c2
+labelops-pr-security-scan.md: 7dd4063d35d2bac6b0edf238e72a1ffe2570d0102340dab8064bf1de9ec73ac7
 regression-pr-shepherd.md: 18a65fe1cdf8aa219158f1d610db14078e5ff2f1ac912df2566bf796792395b5
 repo-assist.md: 3775b51d142d22c98e87e48e8ac9d46cdf69e9c8306d5787758a35578dcb1119
 -->
@@ -0,0 +1,55 @@
+---
+applyTo:
+  - "src/Compiler/**/*.{fs,fsi}"
+  - "vsintegration/src/**/*.{fs,fsi}"
+  - "tests/FSharp.Compiler.ComponentTests/**/*.fs"
+  - "tests/FSharp.Compiler.Service.Tests/**/*.fs"
+  - "vsintegration/tests/**/*.fs"
+---
+
+# Code Style: No Bloat
+
+Reviewers read code, not prose. Add bytes only when they pay for themselves.
+
+## Comments
+
+Good names **always** beat comments. Before writing a comment, ask: *can I rename a value, extract a function, or use an active pattern so the comment becomes unnecessary?* If yes, do that instead.
+
+- **Do not** restate what the code says (variable name, type name, attribute name, function signature).
+- **Do not** narrate the algorithm step-by-step. The diff is the algorithm.
+- **Do not** justify design decisions inline ("we chose X over Y because…"). Put rationale in the commit message or PR body.
+- **Do not** leave war-story comments ("previously we did Z, but…", "counter-example: …"). The history is in `git log`.
+- **Do not** write multi-line `///` doc comments for internal helpers whose body is one expression.
+
+Acceptable comments answer **why**, not **what**, and only when the *why* is non-obvious and cannot be expressed by renaming:
+- Workarounds for compiler/runtime bugs (link the bug).
+- Performance constraints invisible from the code shape ("inner loop runs 50M times per typecheck").
+- Cross-file invariants the code itself can't enforce.
+
+If you are tempted to write `// This is intentional`, change the code so the intent is structural, not decorative.
+
+## Code shape
+
+- Compact, idiomatic F#: pattern matching over `if`/`elif` ladders; active patterns where they remove duplication.
+- Low cyclomatic complexity per function. Extract helpers — even one-line ones — when a name clarifies a step.
+- Prefer module-level `let` over big bodies with nested locals.
+- New file > bloating an existing 5000-line file when adding a self-contained concept.
+
+## Test code
+
+Tests get a touch more leeway for explanation, but the same rules largely apply:
+
+- One parametrized test (`[<Theory>]`, `[<InlineData>]`, or a `for/yield` over inputs) > five copy-pasted tests.
+- Module-level constants for shared paths (`Path.Combine` for OS neutrality), shared source strings, and shared expected outputs.
+- Helpers like `parseAndCheck code` over reinventing the setup per test.
+- Don't reinvent an entire `.fs` file inside each test when one shared module-level binding will do.
+
+## PR scope
+
+**Not paid by LOC.** Large PRs are typically shitty PRs. If the diff has 1000+ lines, split it.
+- Cleanup commits separate from feature commits.
+- No "phase tag" / "transitional measure" / "follow-up" comments left behind — either do it now in a follow-up commit, or file an issue. Don't leave breadcrumbs in the code.
+
+## When in doubt
+
+Delete the comment, rename the value, and re-read. If the code is still unclear, *that* is what needs fixing — not the comment.
@@ -1,48 +1,56 @@
 ---
 name: fsharp-diagnostics
-description: "Always invoke after editing .fs files. Provides fast parse/typecheck feedback without a full dotnet build. Prefer this over dotnet build for iterative changes. Also finds symbol references and inferred type hints."
+description: Always invoke after editing `.fs` files under `src/Compiler/`. Fast parse/typecheck without `dotnet build`, plus symbol references and inferred type hints. Use whenever the user asks about F# errors, compile errors, type inference, finding usages, or renaming a symbol in the compiler tree.
 ---
 
 # F# Diagnostics
 
-**Scope:** `src/Compiler/` files only (`FSharp.Compiler.Service.fsproj`, Release, net10.0).
+**Scope:** `src/Compiler/` files only.
 
-## Setup (run once per shell session)
+## Setup (once per session)
 
-```bash
-GetErrors() { "$(git rev-parse --show-toplevel)/.github/skills/fsharp-diagnostics/scripts/get-fsharp-errors.sh" "$@"; }
+Requires pwsh 7+ (`brew install powershell` / `winget install Microsoft.PowerShell` / `apt install powershell`).
+
+```pwsh
+function GetErrors { & "$(git rev-parse --show-toplevel)/.github/skills/fsharp-diagnostics/scripts/get-fsharp-errors.ps1" @args }
 ```
 
+From bash/zsh without a function: `pwsh -File <repo>/.github/skills/fsharp-diagnostics/scripts/get-fsharp-errors.ps1 <args>`.
+
 ## Parse first, typecheck second
 
-```bash
-GetErrors --parse-only src/Compiler/Checking/CheckBasics.fs
-```
-If errors → fix syntax. Do NOT typecheck until parse is clean.
-```bash
-GetErrors src/Compiler/Checking/CheckBasics.fs
+```pwsh
+GetErrors -ParseOnly src/Compiler/Checking/CheckBasics.fs   # syntax only
+GetErrors            src/Compiler/Checking/CheckBasics.fs   # full typecheck
 ```
+Fix all parse errors before typechecking; type errors on top of bad syntax are noise.
 
-## Find references for a single symbol (line 1-based, col 0-based)
+## Symbol references (line 1-based, col 0-based)
 
-Before renaming or to understand call sites:
-```bash
-GetErrors --find-refs src/Compiler/Checking/CheckBasics.fs 30 5
+```pwsh
+GetErrors -FindRefs src/Compiler/Checking/CheckBasics.fs 30 5
 ```
+Use before any rename.
 
-## Type hints for a range selection (begin and end line numbers, 1-based)
+## Type hints (line range, 1-based)
 
-To see inferred types as inline `// (name: Type)` comments:
-```bash
-GetErrors --type-hints src/Compiler/TypedTree/TypedTreeOps.fs 1028 1032
+Returns the range with inferred types as inline `// (name: Type)` comments:
+```pwsh
+GetErrors -TypeHints src/Compiler/TypedTree/TypedTreeOps.Transforms.fs 100 120
 ```
 
 ## Other
 
-```bash
-GetErrors --check-project   # typecheck entire project
-GetErrors --ping
-GetErrors --shutdown
+```pwsh
+GetErrors -CheckProject   # typecheck entire project
+GetErrors -Ping           # liveness check, no side effects
+GetErrors -Shutdown
 ```
 
-First call starts server (~70s cold start, set initial_wait=600). Auto-shuts down after 4h idle. ~3 GB RAM.
+## Timing
+
+- First real call after a fresh clone: server build + in-memory warmup, 5–15 min → `initial_wait=1200`.
+- After warmup: real commands answer in seconds → `initial_wait=180`.
+- `-Ping` / `-Shutdown`: sub-second; never trigger build or warmup.
+
+Auto-shuts down after 4h idle; ~3 GB RAM while running.