Set Up GitHub Repository Configuration

[mikkihugo]

User description

Added comprehensive caching strategy to significantly speed up Copilot workspace setup:

• Add _build cache for compiled artifacts (prevents full recompilation)
• Add PLT cache for Dialyzer type checking (very slow to rebuild)
• Add explicit compilation steps (deps.compile + compile)
• Improve cache keys to include source code hashes for better hit rates

Expected performance improvement: 2-4x faster setup (from ~3min to ~30sec on cache hits)

Mirrors the optimization strategy from comprehensive-ci.yml workflow.

What does this PR do?

Brief description of the changes made in this pull request.

Related Issues

Fixes #123
or
Related to #456

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Testing

• Tests added for new functionality
• All tests passing locally (mix test)
• Code quality checks passing (mix quality)

Checklist

• Code follows the style guidelines (run mix format)
• Documentation updated (if user-facing change)
• CHANGELOG.md updated (for new features/breaking changes)
• No new warnings introduced (mix credo --strict)
• Types are correct (Dialyzer happy)
• No breaking changes (or documented in CHANGELOG)

Screenshot (if applicable)

N/A

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PR Type

Enhancement

---

Description

• Add comprehensive caching for Mix dependencies, compiled build artifacts, and Dialyzer PLT files

• Implement multi-level cache keys including source code hashes for better hit rates

• Add explicit compilation steps (deps.compile and compile) to optimize build process

• Expected 2-4x performance improvement on cache hits (from ~3min to ~30sec)

---

Diagram Walkthrough

flowchart LR
  A["Setup Elixir"] --> B["Cache Mix deps"]
  B --> C["Cache build artifacts"]
  C --> D["Cache PLT files"]
  D --> E["Install dependencies"]
  E --> F["Compile dependencies"]
  F --> G["Compile application"]

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File Walkthrough

Relevant files

Enhancement

copilot-setup-steps.yml Add multi-level caching and explicit compilation steps      .github/workflows/copilot-setup-steps.yml Renamed cache step from "Restore Elixir dependencies cache" to "Cache Mix dependencies" with improved key naming Added new cache step for compiled build artifacts (_build directory) with source code hash in key Added new cache step for Dialyzer PLT files (priv/plts directory) with multi-level restore keys Added explicit mix deps.compile and mix compile steps after dependency installation Improved cache key strategy to include hashFiles('lib/**/*.ex') for better cache invalidation +29/-4

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[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
🟢	No security concerns identified No security vulnerabilities detected by AI analysis. Human verification advised for critical code.
Ticket Compliance
⚪	🎫 No ticket provided Create ticket/issue
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
⚪	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: No auditing: The added workflow steps focus on caching and builds and do not implement or modify any application audit logging for critical actions, which may be outside the scope of this CI change. Referred Code - name: Cache Mix dependencies uses: actions/cache@v4 with: path: deps key: ${{ runner.os }}-mix-deps-${{ hashFiles('**/mix.lock') }} restore-keys: | ${{ runner.os }}-mix-deps- - name: Cache compiled build uses: actions/cache@v4 with: path: _build key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} restore-keys: | ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}- ${{ runner.os }}-mix-build- - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts ... (clipped 18 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Limited error handling: Newly added steps (dependency install/compile) do not include explicit retries or failure context messaging beyond default GitHub Actions behavior, which may be acceptable for CI but lacks explicit edge-case handling. Referred Code - name: Install dependencies run: mix deps.get - name: Compile dependencies run: mix deps.compile - name: Compile application run: mix compile Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
🟢	No security concerns identified No security vulnerabilities detected by AI analysis. Human verification advised for critical code.
Ticket Compliance
⚪	🎫 No ticket provided Create ticket/issue
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
⚪	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Not Applicable Scope: The added workflow steps are CI caching and build operations and do not implement or affect runtime audit trails; verification requires broader repository context beyond this diff. Referred Code - name: Cache Mix dependencies uses: actions/cache@v4 with: path: deps key: ${{ runner.os }}-mix-deps-${{ hashFiles('**/mix.lock') }} restore-keys: | ${{ runner.os }}-mix-deps- - name: Cache compiled build uses: actions/cache@v4 with: path: _build key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} restore-keys: | ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}- ${{ runner.os }}-mix-build- - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts ... (clipped 18 lines) Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Limited Error Handling: New steps like dependency installation and compilation do not include explicit retry or failure-context logging, which may hinder diagnosing CI edge cases. Referred Code - name: Install dependencies run: mix deps.get - name: Compile dependencies run: mix deps.compile - name: Compile application run: mix compile Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: External Inputs Absent: The CI workflow changes handle caching and builds without processing external user inputs; security validation concerns are out of scope for this diff but require repo-wide review. Referred Code - name: Cache Mix dependencies uses: actions/cache@v4 with: path: deps key: ${{ runner.os }}-mix-deps-${{ hashFiles('**/mix.lock') }} restore-keys: | ${{ runner.os }}-mix-deps- - name: Cache compiled build uses: actions/cache@v4 with: path: _build key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} restore-keys: | ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}- ${{ runner.os }}-mix-build- - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts ... (clipped 14 lines) Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
High-level	Broaden cache key source file glob The cache keys for the _build and priv/plts directories should include all Elixir source files by using a glob like /*.ex. This prevents stale caches if the project is an umbrella application or has source code outside the lib directory.** Examples: .github/workflows/copilot-setup-steps.yml [66] key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} .github/workflows/copilot-setup-steps.yml [75] key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} Solution Walkthrough: Before: - name: Cache compiled build uses: actions/cache@v4 with: path: _build key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} ... - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} ... After: - name: Cache compiled build uses: actions/cache@v4 with: path: _build key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('**/*.ex') }} ... - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('**/*.ex') }} ... Suggestion importance[1-10]: 9 __ Why: This suggestion correctly identifies a critical flaw in the cache key logic that could lead to stale builds, significantly improving the CI's reliability and robustness for different project structures.	High
General	Optimize build cache for faster builds Optimize the build cache key by removing the hash of application source files (lib//*.ex). This prevents unnecessary cache invalidations on code changes, leveraging mix compile's ability to only recompile changed files and speeding up the CI pipeline.** .github/workflows/copilot-setup-steps.yml [62-69] - name: Cache compiled build uses: actions/cache@v4 with: path: _build - key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} + key: ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }} restore-keys: | - ${{ runner.os }}-mix-build-${{ hashFiles('**/mix.lock') }}- ${{ runner.os }}-mix-build- Apply / Chat Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies that including the application source files in the build cache key is inefficient, as it forces a full dependency recompile on any code change, and the proposed fix significantly improves CI performance.	Medium
	Optimize PLT cache for faster analysis Optimize the PLT cache key by removing the hash of application source files (lib//*.ex). This avoids slow and unnecessary PLT rebuilds on code changes, significantly speeding up the static analysis step in CI.** .github/workflows/copilot-setup-steps.yml [71-78] - name: Cache PLT files uses: actions/cache@v4 with: path: priv/plts - key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('lib/**/*.ex') }} + key: ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }} restore-keys: | - ${{ runner.os }}-plt-${{ hashFiles('**/mix.lock') }}- ${{ runner.os }}-plt- Apply / Chat Suggestion importance[1-10]: 8 __ Why: The suggestion correctly points out that including application source files in the PLT cache key is inefficient, as it forces a slow PLT rebuild on every code change, and the proposed fix significantly improves CI performance.	Medium
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