Fix symlink path resolution, add Makefile for streamlined global installation, and optimize trailing slash normalization

[R0X4R]

Issue Description

Problem

1. Symlink Asset Resolution Breakdowns: When executing the compiled nomore403 binary via a symbolic link, the tool fails to locate the default payloads/ directory. This happens because the runtime context evaluates relative to the symlink file path rather than the underlying binary destination.
2. Global Installation Configuration Gaps: Users who install the tool via go install or run it globally have to manually move or pass the -f flag to point to the payloads directory, leading to a clunky user experience for a system-wide CLI utility.
3. Redundant Code Patterns: The initialization checks for trailing slashes on target URIs use multi-line conditional statements that can be simplified into a more idiomatic Go pattern.

Proposed Solution

1. Implement filepath.EvalSymlinks: Update the path resolution inside cmd/root.go to follow symbolic links to their absolute source before attaching the fallback /payloads directory string.
2. Introduce a Configuration Makefile: * Add a make build target that compiles the binary locally while deploying default payloads to a persistent global directory (~/.nomore403/payloads).

• Add a make install target that handles dynamic GOBIN/GOPATH extraction via go env for a robust, zero-download installation footprint.
• Include an automated -h verification step on successful compilation.

3. Refactor Code Noise: Replace the conditional slash checks inside runAutocalibrate with an unconditional strings.TrimSuffix(options.uri, "/") + "/" statement and remove any verified dead code wrappers.

I have implemented these fixes locally across cmd/root.go and a new root-level Makefile and can submit a Pull Request if the maintainers are open to these improvements.