Update docs and install script for Stack/GHC 9.10.3

Switch README and CLAUDE.md from cabal to stack commands, update GHC
version references, add pkg-config to install-deps.sh, and add Stack
as the recommended build method.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -10,31 +10,36 @@ Docster is a Haskell CLI tool that converts Markdown files with embedded Mermaid
 
 ### Build
 ```bash
-cabal build
+stack build
 ```
 
 ### Run
 ```bash
 # Convert to PDF
-cabal run docster -- -pdf path/to/file.md
+stack exec docster -- -pdf path/to/file.md
 
-# Convert to HTML  
-cabal run docster -- -html path/to/file.md
+# Convert to HTML
+stack exec docster -- -html path/to/file.md
+```
+
+### Test
+```bash
+stack test
 ```
 
 ### Test a single file
 ```bash
-cabal run docster -- -pdf mermaid-to-svg/sample.md
+stack exec docster -- -pdf mermaid-to-svg/sample.md
 ```
 
 ### Clean build artifacts
 ```bash
-cabal clean
+stack clean
 ```
 
 ### Interactive development
 ```bash
-cabal repl
+stack repl
 ```
 
 ## Architecture
@@ -57,17 +62,11 @@ The tool uses Pandoc's AST transformation capabilities to:
 ## Dependencies
 
 External requirements:
-- GHC 9.12.2 and Cabal 3.16 (install via ghcup)
-- Pandoc library
+- Stack (install via ghcup) — manages GHC 9.10.3 automatically via lts-24.34
+- Pandoc library (Haskell dependency, pulled by Stack)
 - TeX Live (for PDF generation via XeLaTeX)
 - Mermaid CLI (`npm install -g @mermaid-js/mermaid-cli`)
-
-To install GHC and Cabal:
-```bash
-source ~/.ghcup/env && ghcup install ghc 9.12.2
-source ~/.ghcup/env && ghcup install cabal 3.16.0.0
-source ~/.ghcup/env && ghcup set ghc 9.12.2
-```
+- pkg-config, libgmp-dev, libffi-dev, zlib1g-dev (see `install-deps.sh`)
 
 ## Common Issues
 

README.md

@@ -13,12 +13,14 @@ Mermaid code blocks (```mermaid) will be rendered to SVG and embedded.
 
 ### Prerequisites
 
-First install the required system dependencies:
+Install the required system dependencies (Ubuntu/Debian):
 
 ```bash
 ./install-deps.sh
 ```
 
+This installs build-essential, libgmp-dev, libffi-dev, zlib1g-dev, pkg-config, and TeX Live packages for PDF generation.
+
 ### Install Haskell toolchain
 
 Install ghcup (Haskell toolchain installer):
@@ -28,13 +30,26 @@ curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
 source ~/.ghcup/env
 ```
 
-Install specific GHC and Cabal versions:
+#### Option A: Build with Stack (recommended)
+
+Stack manages its own GHC installation automatically.
 
 ```bash
-ghcup install ghc 9.12.2
+ghcup install stack
+stack build
+stack install
+```
+
+This uses the resolver defined in `stack.yaml` (currently lts-24.34 / GHC 9.10.3).
+
+#### Option B: Build with Cabal
+
+```bash
+ghcup install ghc 9.10.3
 ghcup install cabal 3.16.0.0
-ghcup set ghc 9.12.2
+ghcup set ghc 9.10.3
 ghcup set cabal 3.16.0.0
+cabal install --installdir=$HOME/.local/bin
 ```
 
 ### Install Mermaid CLI
@@ -43,18 +58,24 @@ ghcup set cabal 3.16.0.0
 npm install -g @mermaid-js/mermaid-cli
 ```
 
-### Build and install docster
+### PATH setup
+
+Make sure the install location is in your PATH. Add to your shell config if needed:
 
 ```bash
-cabal install --installdir=$HOME/.local/bin
-```
+# For Stack
+export PATH="$HOME/.local/bin:$PATH"
 
-Make sure `~/.local/bin` is in your PATH. Add to your shell config if needed:
-
-```bash
+# For Cabal
 export PATH="$HOME/.local/bin:$PATH"
 ```
 
 ## Development
 
+```bash
+stack build    # compile
+stack test     # run tests
+stack repl     # interactive REPL
+```
+
 See [agents.md](agents.md) for information about the Claude Code agents used for Haskell refactoring in this project.

install-deps.sh

@@ -1,2 +1,2 @@
 sudo apt update
-sudo apt install -y build-essential libgmp-dev libffi-dev zlib1g-dev texlive-latex-base texlive-fonts-recommended texlive-latex-extra texlive-xetex
+sudo apt install -y build-essential pkg-config libgmp-dev libffi-dev zlib1g-dev texlive-latex-base texlive-fonts-recommended texlive-latex-extra texlive-xetex

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-22.39  # GHC 9.12.2 compatible
+resolver: lts-24.34  # GHC 9.10.3
 
 packages:
 - .

stack.yaml.lock

@@ -6,7 +6,7 @@
 packages: []
 snapshots:
 - completed:
-    sha256: 6c5aeace2ca5ecde793a9e0acfaa730ec8f384aa2f6183a2a252f5f9ec55d623
-    size: 720039
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/22/39.yaml
-  original: lts-22.39
+    sha256: 45b164eaf5c16bd220d2c5d7ab9a66ca0cfbcde7753703a5cb3549172adde813
+    size: 728959
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/24/34.yaml
+  original: lts-24.34