[roll] Roll fuchsia [check-licenses] Refactor result package and fix resource leaks

This change addresses numerous resource leaks, concurrency risks, and
validation bugs within the `result` package. It also overhauls the
testing strategy to use targeted unit tests rather than
integration-level golden files.

* Resource Leak Fixes: Resolved three massive File Descriptor (FD)
  exhaustion bugs across `template.go` and `result.go` (including
  `saveReadmeFuchsiaFiles` and `compressTarGZ`) by explicitly
  closing files during loop iterations rather than relying on
  `defer`.

* OOM Optimization: Rewrote `compressTarGZ` to stream the metrics
  archive directly to disk via `os.Create` rather than buffering
  the entire `.tar.gz` into RAM, preventing Out-Of-Memory crashes
  on large workspaces.

* Concurrency Safety: Replaced all direct accesses to global state
  in `result.go`, `checks.go`, and `world.go` (like
  `project.FilteredProjects` and `p.LicenseFiles`) with their new
  thread-safe accessors (e.g., `project.GetAllFilteredProjects()`)
  to prevent data races.

* Linter Bug Fixes:

  * Rewrote the HTTP link checker
    (`AllComplianceWorksheetLinksAreGood`) to use a bounded worker
    pool (10 goroutines) with strict connection timeouts and
    Keep-Alive drain/close logic to prevent blocking the main thread
    for minutes.

  * Fixed `AllLicenseTextsMustBeRecognized` to correctly catch and
    flag files that return empty `Matches` arrays from the classifier.

  * Fixed a malformed JSON struct tag in `config.go` that was
    causing the linter checks to silently ignore `_config.json`
    allowlists.

* Code Cleanup: Moved the contents of `init.go` into `config.go` and
  deleted `init.go`. Fixed a bug where `compressTarGZ` would compress
  the entire current working directory if `OutDir` was left empty.

* Testing: Deleted `testdata/` and created `checks_test.go`,
  `config_test.go`, `template_test.go`, and `world_test.go` using
  dynamic `t.TempDir()` scaffolding, aggressively covering the HTTP
  crawler, template execution, config merging, and deduplication logic.

* Documentation: Added a comprehensive `README.md` documenting the
  architecture and the deduplication algorithm in `world.go`.

* Licensing Fixes:
  * Modified `checks.go` to explicitly allow new "Permissive",
    "Notice", and "Unencumbered" match types without requiring explicit
    project allowlists. This is a for organizational purposes; I will work to re-categorize all of these license patterns in follow-up commits.
  * Added a temporary "Unclassified" category bypass.
  * Extracted missing license patterns into the `assets/patterns/` tree.
  * Allowlisted test stubs, marker files, and unclassifiable segments.
  * Updated READMEs to correctly specify license file formats.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1569135
Original-Revision: e050916f1e5c29005afa34df5c3c0fa1f415970b
GitOrigin-RevId: 29ce59a2aa8705013e10df070faefe9b30ebcff0
Change-Id: I40e681fbd783b9f970288377bd37a5d3508d3cab