Fix python f-string backslash syntax compatibility

[rev2ret]

Resolves a syntax error (f-string expression part cannot include a backslash) when running the long-context-evaluation lesson script on Python versions prior to 3.12 (e.g. 3.11.4).

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 9ddf02db-44c2-47c1-b215-a6773dd002f9

📥 Commits

Reviewing files that changed from the base of the PR and between 708b3d6 and 06a8d07.

📒 Files selected for processing (2)

• ROADMAP.md
• site/data.js

✅ Files skipped from review due to trivial changes (2)

• site/data.js
• ROADMAP.md

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📝 Walkthrough

Walkthrough

This PR contains four independent small updates: a single-line grid header formatting change using str.format instead of f-strings, ROADMAP documentation updates adjusting total time to ~950 hours and adding two Phase 11 lessons, an initial BACKERS.md file with a thank-you message, and an auto-generated site build timestamp bump.

Changes

Docs and misc code tweaks

Layer / File(s)	Summary
Grid header formatting phases/05-nlp-foundations-to-advanced/28-long-context-evaluation/code/main.py	Grid header print in run_niah_grid switches to str.format width specifiers for column alignment instead of f-string formatting.
ROADMAP time and lessons update ROADMAP.md	Total estimated time updated to ~950 hours, Phase 11 estimate increased from ~17 to ~19 hours, and two new Phase 11 lessons added (LangGraph state machines and agent framework tradeoffs).
Add BACKERS.md BACKERS.md	Initial BACKERS.md file created with a thank-you message and a placeholder indicating no backers are listed yet.
Site build timestamp bump site/data.js	Auto-generated build metadata comment updated to a newer timestamp.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Fix python f-string backslash syntax compatibility' directly addresses the main change in the PR: reformatting the header row in main.py to fix f-string backslash syntax errors for Python < 3.12 compatibility.
Description check	✅ Passed	The description accurately explains the purpose of the PR: resolving a syntax error with f-strings in the long-context-evaluation lesson script for Python versions prior to 3.12.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 ast-grep (0.42.3)

site/data.js

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Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@README.md`:
- Line 260: Remove the duplicate anchor elements that were added (e.g., <a
id="phase-1"></a>) which collide with the existing <details id="phase-1"> IDs;
for each phase-N case listed (phase-1, phase-2, etc.) delete the newly inserted
<a id="phase-N"></a> lines so that only the <details id="phase-N"> element
retains that id and prevents ambiguous `#phase-N` navigation.

In `@ROADMAP.md`:
- Line 7: The "Total estimated time" summary (~316 hours) conflicts with the
footer total (~950 hours); update the inconsistent figure so both the "Total
estimated time" line and the footer total (the "~316 hours" and "~950 hours
estimated" strings) reflect the same reconciled total—either recompute the
correct aggregate and replace both occurrences or change the single-line summary
to match the footer; ensure you update the exact text "Total estimated time:
~316 hours" and the footer string "~950 hours estimated" to the agreed value.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 4b97733c-000a-4699-81fa-3da4ff6f13f5

📥 Commits

Reviewing files that changed from the base of the PR and between ee53036 and 708b3d6.

📒 Files selected for processing (4)

• BACKERS.md
• README.md
• ROADMAP.md
• site/data.js

✅ Files skipped from review due to trivial changes (2)

• BACKERS.md
• site/data.js