chore: update passwap v0.12.1 and align hash validation defaults/errors (#12179)

# Which Problems Are Solved

- Upgrading to `zitadel/passwap` v0.12.1 introduced new encoded-hash
validation paths that still had review feedback open.
- Secret hasher defaults were internally inconsistent (`Hasher.Cost: 4`
vs `Limits.Bcrypt.MinCost: 10`), which could reject hashes created by
the configured hasher.
- New validation error IDs/messages and test coverage needed to be
aligned with project conventions and expected behavior branches.

# How the Problems Are Solved

- Kept the dependency upgrade to `zitadel/passwap` v0.12.1 and completed
the validation integration.
- Updated `ValidateEncodedHash` error handling in
`internal/crypto/passwap.go` to:
  - use unique random-style error IDs,
  - return `Errors.Hash.NotSupported` for no-verifier cases,
  - keep invalid-hash branches mapped to invalid argument errors.
- Expanded `TestHasher_ValidateEncodedHash` in
`internal/crypto/passwap_test.go` to cover and assert:
  - bounds error branch,
  - no-verifier branch,
  - generic invalid-hash branch,
  - expected ZITADEL error IDs/messages.
- Restored lost inline verifier-context comments for argon2 and md5plain
verifier entries.

# Additional Changes

- Added the missing explanatory `Limits` comment for `SecretHasher` in
`cmd/defaults.yaml`.
- Corrected `SecretHasher.Limits.Bcrypt.MinCost` from `10` to `4` to
match the configured default bcrypt cost and avoid configuration
footguns.

# Additional Context

- Follow-up for PR review feedback in
https://github.com/zitadel/zitadel/pull/12179#pullrequestreview-4313121965

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Livio Spring <[email protected]>

internal/command/main_test.go

@@ -293,6 +293,14 @@ func (h plainHasher) Hash(password string) (string, error) {
 	return strings.Join([]string{"", "plain", h.x, password}, "$"), nil
 }
 
+func (h plainHasher) Validate(encoded string) (verifier.Result, error) {
+	nodes := strings.Split(encoded, "$")
+	if len(nodes) != 4 || nodes[1] != "plain" {
+		return verifier.Skip, nil
+	}
+	return verifier.OK, nil
+}
+
 func (h plainHasher) Verify(encoded, password string) (verifier.Result, error) {
 	nodes := strings.Split(encoded, "$")
 	if len(nodes) != 4 || nodes[1] != "plain" {