feat(backlog): add backlog add for interactive issue creation

[djm81]

Description

This PR delivers backlog interactive issue creation and provider-aware mapping setup for backlog workflows.

Summary:

• Adds specfact backlog add with interactive and non-interactive creation flow, hierarchy validation, DoR checks, sprint/iteration selection, parent selection, and provider-aware payload mapping.
• Extends adapters with unified create_issue(project_id, payload) and centralized retry policy behavior for write operations.
• Adds specfact backlog init-config and expands specfact backlog map-fields to multi-provider setup (ado, github) with canonical persistence in .specfact/backlog-config.yaml.
• Enhances GitHub creation flow with native sub-issue parent linking and optional issue type / ProjectV2 type mapping support.
• Updates docs and changelog for 0.36.0.

Fixes #173

New Features #173

Contract References:

• BacklogAdapterMixin.create_issue(...) contract extension.
• GitHubAdapter.create_issue(...) and AdoAdapter.create_issue(...) contract-enforced provider implementations.

Type of Change

Please check all that apply:

• 🐛 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 not work as expected)
• 📚 Documentation update
• 🔒 Contract enforcement (adding/updating @icontract decorators)
• 🧪 Test enhancement (scenario tests, property-based tests)
• 🔧 Refactoring (code improvement without functionality change)

Contract-First Testing Evidence

Required for all changes affecting CLI commands or public APIs:

Contract Validation

• Runtime contracts added/updated (@icontract decorators on public APIs)
• Type checking enforced (@beartype decorators applied)
• CrossHair exploration completed: hatch run contract-test-exploration
• Contract violations reviewed and addressed

Test Execution

• Contract validation: hatch run contract-test-contracts ✅
• Contract exploration: hatch run contract-test-exploration ✅
• Scenario tests: hatch run contract-test-scenarios ✅
• Full test suite: hatch run contract-test-full ✅

Test Quality

• CLI commands tested with typer test client
• Edge cases covered with Hypothesis property tests
• Error handling tested with invalid inputs
• Rich console output verified manually or with snapshots

How Has This Been Tested?

Contract-First Approach: Added/updated contracts and adapter APIs first-class, then validated via unit/regression tests and project quality gates.

Manual Testing

• Tested CLI commands manually
• Verified rich console output
• Tested with different input scenarios
• Checked error messages for clarity

Automated Testing

• Contract validation passes
• Property-based tests cover edge cases
• Scenario tests cover user workflows
• All existing tests still pass

Test Environment

• Python version: 3.11+
• OS: Linux

Checklist

• My code follows the style guidelines (PEP 8, ruff format, isort)
• I have performed a self-review of my code
• I have added/updated contracts (@icontract, @beartype)
• I have added/updated docstrings (Google style)
• I have made corresponding changes to documentation
• My changes generate no new warnings (basedpyright, ruff, pylint)
• All tests pass locally
• I have added tests that prove my fix/feature works
• Any dependent changes have been merged

Quality Gates Status

• Type checking ✅ (hatch run type-check)
• Linting ✅ (hatch run lint)
• Contract validation ✅ (hatch run contract-test-contracts)
• Contract exploration ✅ (hatch run contract-test-exploration)
• Scenario tests ✅ (hatch run contract-test-scenarios)

Screenshots/Recordings (if applicable)

CLI-focused change; no screenshots attached.

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Note

Medium Risk
Introduces new provider write paths (GitHub/ADO issue creation, GraphQL mutations) and shared retry behavior; mistakes could create incorrect or duplicate backlog items despite test coverage.

Overview
Adds interactive backlog item creation via new specfact backlog add, including non-interactive mode, multiline body/AC capture, priority/story points, DoR validation, sprint/iteration selection (ADO), and parent selection with configurable creation_hierarchy validation.

Extends the backlog adapter contract with create_issue() and implements it for GitHub and Azure DevOps, adds centralized retry behavior for write operations (duplicate-safe for non-idempotent calls), and enhances GitHub creates with native parent sub-issue linking plus optional Issue Type / ProjectV2 Type field updates from .specfact/backlog-config.yaml or custom config.

Introduces backlog-scoped config loading from .specfact/backlog-config.yaml, adds specfact backlog init-config, expands backlog map-fields into a multi-provider guided flow with canonical persistence, updates docs/command reference, and bumps version to 0.36.0 with new tests covering the added flows.

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