[JoannaaKL]

Summary

Integer parameter parsing now rejects values at or above 2^63. Before, they slipped past the range check and came out as MinInt (amd64) or MaxInt (arm64).

Why

math.MaxInt64 can't be represented as a float64 and rounds up to 2^63, so f > math.MaxInt lets 2^63 through. That includes "9223372036854775807". Go doesn't define the result of converting an out-of-range float to an int.
Fixes #3489

What changed

• pkg/github/params.go: added an inSignedIntRange helper that checks against the exact 2^(n-1) bound before converting. toInt and toInt64 now use it; toInt64's old round-trip check also missed this case on arm64.
• pkg/github/security_outputs.go, pkg/github/typed_read_normalizers.go: replaced the same broken check with the helper.
• Boundary tests for the helper, OptionalIntParam, RequiredBigInt and both normalizers. The new rejection cases fail on main.

This covers both #3493 and #3565, and also fixes toInt64.

MCP impact

• No tool or API changes
  Schemas are unchanged. Values ≥ 2^63 now return the existing range errors instead of being sent to the API.

Prompts tested (tool changes only)

• N/A

Security / limits

• No security or limits impact
  Input validation only.

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Lint & tests

• Linted locally with ./script/lint: passed, 0 issues (golangci-lint v2.14.0)
• Tested locally with ./script/test: passed

Docs

• Not needed
• Updated (README / docs / examples)

[Copilot]

🟢 Approval recommended

No active review issues were identified for the integer-overflow validation changes.

No open issues 🎉

What changed in this PR

Fixes integer overflow validation in GitHub MCP Server parameter parsing, addressing #3489 and covering the fixes proposed in #3493 and #3565 without changing tool schemas.

Changes:

• Adds a shared signed-integer range check using an exact, exclusive upper bound.
• Applies the check before integer conversion in parameter parsers and both input normalizers.
• Adds boundary tests for rejected overflow values and accepted limits.

File	Description
pkg/​github/​typed_security_outputs_test.go	Tests security argument overflow rejection and valid input.
pkg/​github/​typed_search_outputs_test.go	Tests out-of-range pagination string rejection.
pkg/​github/​typed_read_normalizers.go	Uses the shared range check for pagination string conversion.
pkg/​github/​security_outputs.go	Uses the shared range check for security integer arguments.
pkg/​github/​params.go	Adds the range helper and checks bounds before int and int64 conversion.
pkg/​github/​params_test.go	Adds helper, optional integer, and required big-integer boundary tests.

_{Review effort: Balanced (auto)}