Build comprehensive DP-700 objective-aligned study content

[troyscott]

Status: ready for human review

This PR completes the comprehensive DP-700 content build defined in #36. The
book is now an evidence-backed study edition rather than a topic-presence
outline.

Completion summary

• All 10 chapter files render as original study-oriented material
• All 54 objectives from the July 21, 2026 Study Guide are represented
• All 54 objectives pass the ten-category comprehensive content rubric
• All objective evidence points to durable Markdown blocks
• 35,081 chapter words meet the approved 35,000-word depth gate
• 41 Microsoft Learn sources record URL, retrieval timestamp, SHA-256, and chapter mapping
• Every Microsoft Learn link in a chapter has a provenance record
• End-to-end capstones cover governance, orchestration, batch, streaming, operations, incidents, and optimization

Completed execution plan

1. Coverage contract and source audit

• Built the 54-objective subtopic matrix
• Mapped authoritative sources at objective/subtopic level
• Added objective-level completeness metadata and executable tests
• Made unsupported completion claims fail validation

2. Implement and manage

• Completed workspace settings, lifecycle, security/governance, and orchestration

3. Ingest and transform

• Completed loading patterns, detailed Dataflow Gen2/batch coverage, and streaming

4. Monitor and optimize

• Completed monitoring, troubleshooting, and measurement-led performance coverage

5. Final evaluation gate

• Verified technical examples and source provenance
• Completed all-ten-chapter iPhone-width and representative desktop rendering checks
• Completed the 54-objective editorial/evidence audit
• Published docs/dp700-completeness-report.md
• Passed local and GitHub CI validation

Verification

• Ruff format and lint: passed
• mypy: passed across 14 source files
• pytest: 29 passed
• statement coverage: 92.68% (90% required)
• browser-state tests: 5 passed
• GitHub Actions: both quality checks passed
• responsive sweep: all 10 chapters fit a 390 × 844 viewport; representative 1,440 × 900 desktop layout passed; no console errors

See the completeness report for the evidence boundary and detailed counts.

Review boundary

This PR is ready for Troy's human review. Readiness does not authorize merge;
the PR remains the review gate.

Closes #36