[agent-network] Fix codespell typos and exclude false positives

- labelgen word pool: vermillion -> vermilion, racoon -> raccoon.
- codespell ignore list: add flate (Go compress/flate package), recordin
  (a test-local identifier), and unparseable (a valid alternative spelling used
  consistently across identifiers + a metadata-value constant).

management/server/agentnetwork/labelgen/words.go

@@ -84,7 +84,7 @@ var words = []string{
 	"tower", "trail", "tranquil", "tundra", "tulip", "turquoise", "turtle", "twig",
 	"twilight",
 	"umber", "uplands",
-	"valley", "vanilla", "velvet", "venus", "verdant", "verdigris", "vermillion", "violet",
+	"valley", "vanilla", "velvet", "venus", "verdant", "verdigris", "vermilion", "violet",
 	"vista", "vivid", "volcano", "vortex",
 	"walnut", "warbler", "watercress", "waterfall", "wave", "waxwing", "weasel", "westwind",
 	"whale", "whisker", "whisper", "wicker", "wildwood", "willow", "winter", "wisp",
@@ -116,7 +116,7 @@ var words = []string{
 	"papyrus", "paradise", "pasture", "patchwork", "pathway", "peridot", "periwinkle", "petalbloom",
 	"petrel", "petunia", "phlox", "pikeperch", "pinecone", "pioneer", "pipevine", "platypus",
 	"pomelo", "pondweed", "porpoise", "powder", "promise", "puddle", "pumice", "puzzle",
-	"quetzal", "quicksilver", "racoon", "ragwort", "rainforest", "ramble", "rapid", "rascal",
+	"quetzal", "quicksilver", "raccoon", "ragwort", "rainforest", "ramble", "rapid", "rascal",
 	"raspberry", "redbud", "redfern", "redpoll", "reedling", "ringtail", "riverbed", "riverbird",
 	"riverstone", "rockcress", "roebuck", "rosebay", "rosehip", "rosemary", "rowan", "rumble",
 	"runaway", "rustler", "sagebrush", "sailcloth", "salamander", "salsify", "samphire", "sandbar",