fix(history): restore blocked pop navigation by delta

[erictheswift]

Problem

When a browser POP is blocked, createBrowserHistory always calls
window.history.go(1) to undo it. That only reverses a single-entry Back:

• blocking Forward attempts to move farther forward instead of returning;
• blocking go(-2) returns only one entry, leaving the browser URL and the
  router's current location on different history entries.

Fix

Undo the observed POP with its inverse delta: window.history.go(-delta).
For Back this remains go(1), while Forward and multi-entry GO operations now
return to the exact entry from which navigation started.

Tests

Added browser-history regressions for:

• a blocked Forward;
• a blocked multi-entry go(-2).

Validated with:

CI=1 NX_DAEMON=false pnpm nx run @tanstack/history:test:unit --outputStyle=stream --skipRemoteCache
CI=1 NX_DAEMON=false pnpm nx run @tanstack/history:test:types --outputStyle=stream --skipRemoteCache
CI=1 NX_DAEMON=false pnpm nx run @tanstack/history:test:eslint --outputStyle=stream --skipRemoteCache
pnpm exec prettier --check packages/history/src/index.ts packages/history/tests/createBrowserHistory.test.ts

The new tests fail on main with the browser at /two instead of /one for
Forward and /two instead of /three for go(-2), then pass with the inverse
delta.

Summary by CodeRabbit

• Bug Fixes

  • Corrected browser-history restoration when blocked back, forward, or multi-step navigation occurs.
  • Ensured the exact original page is restored after blocked navigation attempts.

• Tests

  • Added coverage for blocked single-step and multi-step browser history navigation.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: d7acba48-65fa-41d8-bda4-136476e9b221

📥 Commits

Reviewing files that changed from the base of the PR and between 179d9b9 and 09c1d1e.

📒 Files selected for processing (2)

• packages/history/src/index.ts
• packages/history/tests/createBrowserHistory.test.ts

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📝 Walkthrough

Walkthrough

Blocked browser-history pop navigations now roll back using the inverse computed delta. Tests cover restoration after blocked forward navigation and blocked multi-entry navigation.

Changes

Browser history rollback

Layer / File(s)	Summary
Delta-based rollback and restoration tests packages/history/src/index.ts, packages/history/tests/createBrowserHistory.test.ts	Blocked pop navigations call history.go(-delta), with tests verifying restoration of the original entry for forward and multi-step navigation and confirming blocker invocation.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: sheraff

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly captures the main change: fixing blocked history pop navigation rollback to use the computed delta.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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