Fixed assets, fully featured: tags, serials, acquisition links, label sheets, the fixed asset register, and an Assets section in the viewer; fix a flaky verify

- core: asset tags (generated PREFIX-0001 or the human's own; unique ignoring case; never reused by another asset) and serial numbers (rules.md B-24); a journaled link from an asset to the entry that acquired it (posted, unreversed, debiting the cost account); fixed_asset_register(as_of), reconciled to the GL (unposted depreciation, unregistered cost)
- store: asset.tagged, asset.serial_set, asset.acquisition_linked journaled, replayed, projected (schema v9); differs_from now also compares control roles and tag history
- config: [books] asset_tag_prefix, default the company's initials without legal-form words
- import: Avery 5160/8160 label sheets with QR codes (geometry vendored from Avery, docs/spec/sources/avery-5160.md); the register as XLSX and PDF
- mcp: register_asset tags (and links) automatically; books.label_asset, books.asset_labels; asset tools take a tag; books.show asset / assets page / register report; export fixed_asset_register (json, csv, xlsx, pdf) and in the CPA package
- viewer: Assets page (register, reconciliation), asset page (identity, schedule posted vs not, entries, documents), Fixed asset register report, global search by tag/serial/description, journal text, needs-attention items
- fix: verify compared snapshot amounts as strings; a zero total summed in hash-map order could print "0" or "0.00", so agreeing books failed verify at random. Now by value (regression test)
- tests: spec-blind suites for tags, register, prefix, store, MCP; label and register PDF/XLSX tests; viewer tests

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX

crates/ledger-gui/src/nav.rs

@@ -1,6 +1,6 @@
 //! Where you are and how you got there: a browser-style history.
 
-use ledger_core::{AccountId, EntryId};
+use ledger_core::{AccountId, AssetId, EntryId};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum ReportKind {
@@ -14,16 +14,18 @@ pub enum ReportKind {
     ArAging,
     ApAging,
     Vendor1099,
+    FixedAssetRegister,
 }
 
 impl ReportKind {
-    pub const ALL: [ReportKind; 10] = [
+    pub const ALL: [ReportKind; 11] = [
         ReportKind::ProfitAndLoss,
         ReportKind::BalanceSheet,
         ReportKind::CashFlow,
         ReportKind::MembersEquity,
         ReportKind::TrialBalance,
         ReportKind::GeneralLedger,
+        ReportKind::FixedAssetRegister,
         ReportKind::TaxSummary,
         ReportKind::Vendor1099,
         ReportKind::ArAging,
@@ -42,6 +44,7 @@ impl ReportKind {
             ReportKind::ArAging => "Receivables aging",
             ReportKind::ApAging => "Payables aging",
             ReportKind::Vendor1099 => "1099 worksheet",
+            ReportKind::FixedAssetRegister => "Fixed asset register",
         }
     }
 }
@@ -56,6 +59,10 @@ pub enum Route {
     Reports(ReportKind),
     Accounts,
     Account(AccountId),
+    /// The fixed asset register.
+    Assets,
+    /// One fixed asset.
+    Asset(AssetId),
     Documents,
     Document(u64),
     Company,
@@ -73,6 +80,7 @@ impl Route {
             Route::Transactions | Route::Entry(_) => Section::Transactions,
             Route::Reports(_) => Section::Reports,
             Route::Accounts | Route::Account(_) => Section::Accounts,
+            Route::Assets | Route::Asset(_) => Section::Assets,
             Route::Documents | Route::Document(_) => Section::Documents,
             Route::Company => Section::Company,
             Route::Journal | Route::JournalEvent(_) => Section::Journal,
@@ -88,19 +96,21 @@ pub enum Section {
     Transactions,
     Reports,
     Accounts,
+    Assets,
     Documents,
     Company,
     Journal,
 }
 
 impl Section {
-    pub const ALL: [Section; 9] = [
+    pub const ALL: [Section; 10] = [
         Section::Overview,
         Section::Cash,
         Section::Profit,
         Section::Transactions,
         Section::Reports,
         Section::Accounts,
+        Section::Assets,
         Section::Documents,
         Section::Company,
         Section::Journal,
@@ -114,6 +124,7 @@ impl Section {
             Section::Transactions => "Transactions",
             Section::Reports => "Reports",
             Section::Accounts => "Accounts",
+            Section::Assets => "Assets",
             Section::Documents => "Documents",
             Section::Company => "Company",
             Section::Journal => "Journal",
@@ -129,6 +140,7 @@ impl Section {
             Section::Transactions => i::LIST_BULLETS,
             Section::Reports => i::FILE_TEXT,
             Section::Accounts => i::TREE_STRUCTURE,
+            Section::Assets => i::PACKAGE,
             Section::Documents => i::FILES,
             Section::Company => i::BUILDINGS,
             Section::Journal => i::SCROLL,
@@ -143,6 +155,7 @@ impl Section {
             Section::Transactions => Route::Transactions,
             Section::Reports => Route::Reports(ReportKind::ProfitAndLoss),
             Section::Accounts => Route::Accounts,
+            Section::Assets => Route::Assets,
             Section::Documents => Route::Documents,
             Section::Company => Route::Company,
             Section::Journal => Route::Journal,