Add achievement export support

docs/export-format.md

@@ -15,7 +15,7 @@ decoder-only offsets.
   "capture_source": "npcap",
   "exporter": {
     "name": "nte-history-exporter",
-    "version": "0.2.1"
+    "version": "0.3.0"
   },
   "banner": {
     "id": "Lottery_Permanent",
@@ -176,6 +176,79 @@ Mystery Box:
 }
 ```
 
+## Achievement export
+
+Achievements are written separately as
+`<user_uid>_Achievements_<date_time>.json`. The document contains only records
+observed in the account's login response; definitions found only in the asset
+mapping are not synthesized into the export.
+
+```json
+{
+  "format": "nte-achievement-export",
+  "format_version": 1,
+  "game": "Neverness to Everness",
+  "source": "live_capture",
+  "capture_source": "npcap",
+  "exporter": {
+    "name": "nte-history-exporter",
+    "version": "0.3.0"
+  },
+  "scan": {
+    "in_game": {
+      "total_achievements": 367,
+      "completed_achievements": 310,
+      "in_progress_achievements": 57
+    },
+    "playstation": {
+      "total_achievements": 35,
+      "completed_achievements": 31,
+      "in_progress_achievements": 4
+    }
+  },
+  "user_uid": "218216016349",
+  "server_id": "23003",
+  "account_region": "EU",
+  "categories": {
+    "battle": [
+      {
+        "id": "Battle_25",
+        "platform": "in_game",
+        "status": "in_progress",
+        "progress": 20,
+        "completed": false,
+        "completed_at": null,
+        "name": "Devil Within II",
+        "description": "Trigger Hexed ×50.",
+        "quality": "high",
+        "target": 50,
+        "rewards": [
+          {"item_id": "Annulith", "amount": 10}
+        ]
+      }
+    ]
+  }
+}
+```
+
+Achievement fields:
+
+- `scan.in_game` and `scan.playstation` separate records visible in game from
+  PlayStation trophy records and report completed/in-progress totals.
+- `categories` groups records by the prefix of their captured ID. The category
+  is therefore not repeated on every record.
+- `status` is `completed` when completion ticks are present and `in_progress`
+  otherwise. An observed compound achievement can be in progress while its
+  numeric `progress` is zero because individual checklist state is server-side.
+- `completed_at` is a decoded UTC time for completed records and `null` for
+  in-progress records.
+- `name`, `description`, `quality`, `target`, and `rewards` are optional display
+  metadata from `mappings/achievements.json`.
+- A newly captured ID missing from the bundled mapping still exports its core
+  captured fields; only optional display metadata is omitted.
+- Asset definitions absent from the network response are not exported because
+  absence cannot distinguish unstarted, locked, or unavailable content.
+
 ## CSV diagnostics
 
 CSV exports are mainly for debugging the decoder. Tools should prefer JSON

docs/limitations.md

@@ -21,5 +21,13 @@ Known limitations:
 - The file adapter reads mitmproxy `.flows` captures for research and testing.
 - Npcap is Windows-only and is not redistributed with this project; Linux and macOS use their system libpcap.
 - Reward keys decode to their reward id string, so unknown rewards still export a usable `reward_id`; display names/ranks come from the mapping JSON files and should be expanded as new rewards appear.
+- Achievement exports contain only records observed in the login response.
+  Asset-only definitions are not synthesized because absence cannot distinguish
+  unstarted, locked, or unavailable content. Unknown captured achievement IDs
+  still export without optional display metadata.
+- Observed achievements have only `completed` and `in_progress` states. Some
+  compound achievements expose numeric progress `0` while the server tracks
+  hidden checklist progress, so every observed record without completion ticks
+  is classified as `in_progress`.
 
 Privacy guardrail: raw packet data must not be included in sanitized exports.

docs/mapping-updates.md

@@ -1,4 +1,4 @@
-# Reward mapping updates
+# Mapping updates
 
 `tools/update_mappings.py` rebuilds `arcs.json`, `characters.json`,
 `items.json`, and `achievements.json` directly from the current
@@ -19,7 +19,7 @@ game whose asset tables evolve over time.
 
 ### GitHub Actions
 
-Run **Update reward mappings** from the repository's Actions tab. The optional
+Run **Update mappings** from the repository's Actions tab. The optional
 `source_ref` input accepts an NTE_Assets branch, tag, or commit and defaults to
 `main`.
 
@@ -68,7 +68,7 @@ python -m pytest -q
 ```
 
 For CI, `--check` exits with status 1 whenever the generated snapshot differs
-from the committed reward mappings. It still writes the staged artifacts.
+from the committed mappings. It still writes the staged artifacts.
 
 ## Source rules
 
@@ -100,7 +100,7 @@ reads or writes the permanent, limited, beginner, or Arc pool mapping files.
 Banner IDs, timestamps, record ordering, format version, and all UID inputs are
 therefore unchanged by mapping synchronization.
 
-Reward IDs and display metadata may change or disappear when the authoritative
-NTE_Assets snapshot changes. Existing exported history files remain unchanged;
-new exports describe rewards using the current asset snapshot. UID stability is
-independent of reward display mappings.
+Reward and achievement IDs or display metadata may change or disappear when
+the authoritative NTE_Assets snapshot changes. Existing exports remain
+unchanged; new exports use the current asset snapshot. UID stability is
+independent of display mappings.

docs/packet-format.md

@@ -1,6 +1,21 @@
 # Packet Format Notes
 
-This prototype supports separate Monopoly, Arc/Gashapon, and Mystery Box history decoders.
+This prototype supports separate Monopoly, Arc/Gashapon, Mystery Box history,
+and achievement decoders.
+
+## Achievements
+
+The account's achievement component arrives in an inbound TCP game-data block
+during login. The block is LZ4-decoded and contains `AchievementRecord` entries.
+Each record provides an achievement ID, an unsigned numeric progress value, and
+a .NET completion timestamp. A non-zero timestamp marks a completed record.
+Every observed record without completion ticks is treated as in progress;
+compound achievements can have server-side checklist progress while exposing a
+numeric value of zero.
+
+Only records present in the network response are exported. Display metadata is
+looked up case-insensitively in `mappings/achievements.json`, because captured
+and asset-table ID casing can differ. Missing metadata never prevents export.
 
 ## Decoder strategy