feat(golang): add extended-stdlib scope and module patterns for symbol capture (#5154)

* feat(golang): add extended-stdlib scope and include patterns for symbol capture

`golang.capture-symbols` decides how much symbol data lands in the SBOM for grype's reachability analysis. It's `none`, `stdlib`, or `all` today, and the useful middle is missing: `stdlib` stops at the standard library, `all` multiplies SBOM size.

A new `extended-stdlib` configurable covers stdlib plus everything under `golang.org/x/`:

```yaml
golang:
  capture-symbols: extended-stdlib
```

Also, a new `capture-symbols-include` configurable for modules that are noisy in your binaries but not everyone's. It's unioned with whatever the scope selects, so it only ever widens:

```yaml
golang:
  capture-symbols: extended-stdlib
  capture-symbols-include:
    - github.com/klauspost/**
```

Patterns are standard doublestar globs, which matters because module paths carry `/v2`-style suffixes:

```yaml
golang:
  capture-symbols-include:
    - github.com/klauspost/*     # compress, but not compress/v2
    - github.com/klauspost/**    # both
    - k8s.io/client-go           # exact match only
```

Ordering is `none` < `stdlib` < `extended-stdlib` < `all`. The existing three values
and the `none` default are unchanged, and the include list is inert under `none`.
Presets compile into glob lists internally, so a single matcher answers "does this
module get symbols" instead of a preset branch sitting next to a separate glob branch.

An unrecognized `capture-symbols` value still falls back to `none`, but warns now
instead of doing it silently. A malformed include pattern warns and gets skipped.

One thing worth a look beyond the feature: the `Symbols` field description in the JSON
schema was wrong after this (it claimed only `all` and `stdlib` populate anything), and
that description lives in the already-published `16.1.10`. Rather than bump a version for
a sentence, `16.1.10` is amended in place and `schema/json/README.md` grows an explicit
exception for description-only changes: descriptions only, no shape change of any kind,
`$id` unchanged. Anything else still needs a bump. Happy to split that into its own PR if
you'd rather review the policy separately.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* refactor(golang): rename capture-symbols-include to capture-symbols-modules

The key's entries are go module paths, and `-include` sitting next to `capture-symbols` reads as plausibly taking symbol or package names instead. Those spellings parse and match nothing, which is quieter than the confusion `-include` was picked to avoid, so the name now says what the list holds.

`golang.CatalogerConfig.CaptureSymbolsModules` and `WithCaptureSymbolsModules` rename with it. Nothing behavioral changes; the key is new in this PR so there is no compatibility surface.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* feat(golang): match capture-symbols-modules across major version suffixes

`github.com/anchore/*` covered `github.com/anchore/syft` and silently stopped covering it the day it became `github.com/anchore/syft/v2`. The config keeps parsing, nothing warns, and symbols quietly go missing from the SBOM. Exact paths had the same hole: `github.com/klauspost/compress` did not cover `compress/v2` either, so no spelling short of `**` survived a major bump.

A major version suffix is part of a module's path but not part of its identity, so patterns are now matched against the module path both with and without it, using `module.SplitPathVersion` from `golang.org/x/mod` (already a direct dep, already used in this package for `PseudoVersion`).

```yaml
golang:
  capture-symbols-modules:
    - github.com/klauspost/*          # compress and compress/v2
    - github.com/klauspost/compress   # same module at every major version
    - github.com/klauspost/compress/v2  # v2 alone
```

Only a trailing suffix is a version, which is Go's own rule. In `github.com/anchore/syft/v2/thing` the `v2` is an ordinary path element naming a major subdirectory a nested module lives in, so it stays literal and `github.com/anchore/**/thing` is how you reach it. `/v0` and `/v1` are not valid suffixes and are left alone.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

schema/json/README.md

@@ -35,3 +35,24 @@ Create the new schema by running `make generate-json-schema` from the root of th
 - If there is an existing schema for the given version and the new schema **does not** match the existing schema, an error is shown indicating to increment the version appropriately (see the "Versioning" section)
 
 ***Note: never delete a JSON schema and never change an existing JSON schema once it has been published in a release!*** Only add new schemas with a newly incremented version. All previous schema files must be stored in the `schema/json/` directory.
+
+### Exception: `description`-only corrections
+
+A published schema may be amended in place for one narrow case: the change touches only `description` text and leaves the data shape identical. Descriptions are documentation carried alongside the schema rather than constraints a validator evaluates, so correcting one cannot invalidate a document that already validated against that version. Minting a new version instead would leave the old one permanently describing the tool incorrectly, and spend a version number on no semantic change.
+
+This applies when **every** one of the following holds:
+
+- the only differences are `description` values
+- no field, type, enum, `required` entry, or `$ref` is added, removed, or altered
+- the `$id` version is unchanged
+
+Anything else, including adding a field that happens to be optional, is a schema change and needs a version bump per the "Versioning" section above.
+
+The generator blocks an in-place edit by design, since it refuses to overwrite a file that differs from what it would produce. To amend one, delete the schema file and regenerate so it is rewritten from the current Go doc comments:
+
+```bash
+rm schema/json/schema-$VERSION.json
+make generate-json-schema
+```
+
+The result is byte-identical to what the generator produces, so do not hand-edit the JSON. Re-running `make generate-json-schema` afterwards should report `No change to the existing schema!`, and `make check-json-schema-drift` should pass. Confirm with `git diff` that the only changes are the intended description lines.