Services editor: filesystem check

Add a "Check filesystem" action to the Services pill:

- SERVICES_FS_MAP: the feature -> FID list transcribed from
  docs/services-editor.md §A (127 file-backed + 34 capability features,
  157 distinct FIDs; a completeness/data test pins it).
- servicesFsReport: pure two-direction check - declared features whose
  mapped files are absent, and present files whose features are
  undeclared.  FID-level (not DF-exact) for this first pass; documented.
- The Check runs the tree probe (once per session) and renders the
  missing/extra lists or the "matches" line, with an FID-level note.

Also fix a doc typo (eCall Data's EF.FDN was written as 6F3A = EF.ADN).
Frontend 1120 + Python 1090 tests green.  (Version/sw bump still
deferred for the decoded-editing batch.)

docs/decoded-editing.md

@@ -300,14 +300,19 @@ de-allocates.
   Each button writes only that file via `/api/write`; an unchanged file is
   skipped and the panel reports each write's result (there is no atomic
   cross-file write).
-- **Filesystem check**: many services declare a DF or EF (ADN -> EF.ADN 6F3A,
-  SPN -> EF.SPN 6F46, GSM Access -> DF.GSM, GPRS -> EF.KcGPRS, …); a second
-  curated table maps a feature to the file(s) it requires.  A **Check** action
-  probes the equipped card for those files (reusing the file-manager presence
-  state / a targeted SELECT) and flags mismatches — a declared service whose
+- **Filesystem check** (implemented, step 4b): many services declare a DF or EF
+  (ADN -> EF.ADN 6F3A, SPN -> EF.SPN 6F46, GSM Access -> DF.GSM-ACCESS 5F3B,
+  GPRS -> EF.KcGPRS, …); a second curated table (`SERVICES_FS_MAP`, keyed by
+  feature name) maps a feature to the FID(s) its `Filesystem` cell declares.
+  A **Check filesystem** action writes the services, probes the file-manager
+  tree once (`pysimFsProbeAll`) and flags mismatches — a declared service whose
   file is absent, or a present file whose service is not declared.  Services
   that map to a capability rather than a file (CHV1 disable, Proactive SIM,
-  …) carry no file check.  The result is cached per `card_session`.
+  …) carry no file check.  This first pass matches **FID-level**, not
+  (DF, FID)-exact as finding 6 asks: the documented FID collisions are not
+  disambiguated and the report says so (`docs/services-editor.md` §B.0).  The
+  last report is kept in memory and dropped with the cached reads on a
+  card-session change.
 
 ### 6.1 Candidates for the same cross-application treatment
 

docs/services-editor.md

@@ -9,8 +9,9 @@
 >
 > Step 4a (the cross-file Services editor: §A's cross-reference, read, render,
 > per-file save) is implemented against §A; the counts below were verified
-> against the PWA's constants by `frontend/tests/services.test.js`.  §B (the
-> filesystem check) is **not** implemented yet.
+> against the PWA's constants by `frontend/tests/services.test.js`.  Step 4b
+> (§B, the filesystem check) is implemented as well - see §B.0 for the
+> representation and the FID-level rule it uses.
 
 **Counts:** SST **59** / UST **150** / IST **22** / EST **3** services →
 **164 feature rows** (10 SIM-only, 85 USIM-only, 5 ISIM-only, 61 shared,
@@ -132,7 +133,7 @@ Names are canonicalised; wording aliases are listed in Notes §1.
 | 93 | Allowed CSG Lists and corresponding indications | | 86 | | | USIM-only | EF.ACSGL 4F81 · EF.CSGT 4F82 · EF.HNBN 4F83 |
 | 94 | Call control on EPS PDN connection by USIM | | 87 | | | USIM-only | capability |
 | 95 | HPLMN Direct Access | | 88 | | | USIM-only | EF.HPLMNDAI 4F4B |
-| 96 | eCall Data | | 89 | | | USIM-only | EF.SDN 6F49 (+ EF.FDN 6F3A) |
+| 96 | eCall Data | | 89 | | | USIM-only | EF.SDN 6F49 (+ EF.FDN 6F3B) |
 | 97 | Operator CSG Lists and corresponding indications | | 90 | | | USIM-only | EF.OCSGL 4F84 · EF.OCSGT 4F85 · EF.OHNBN 4F86 |
 | 98 | Support for SM-over-IP | | 91 | 8 | | shared | capability (ISIM-related: EF.PSISMSC 6FE5) |
 | 99 | Support of CSG Display Control | | 92 | | | USIM-only | capability |
@@ -226,6 +227,49 @@ The FS column in §A is deliverable B, merged for readability. Legend:
 - `?` — no clear file found in either source; needs a human decision.
 - `—` — RFU/reserved.
 
+### B.0 Implemented check (`SERVICES_FS_MAP` + the Check filesystem action)
+
+`frontend/index.html` carries the column as `SERVICES_FS_MAP`, a map keyed by
+the §A feature name (the cross-reference's row identity) whose value is the
+list of **every FID the cell mentions**, in the cell's order:
+
+- `EF.FDN 6F3B (+ EF.EXT2 6F4B)` → `['6F3B', '6F4B']`
+- `DF.GRAPHICS 5F50 → EF.IMG 4F20` → `['5F50', '4F20']` (a DF's FID counts:
+  the DF itself is the file the service gates)
+- `EF.NIA 6F51 (SIM) / 6FD3 (USIM)` → both trees' FIDs
+- `capability` → `[]`; the parenthetical references a capability cell carries
+  (`gate: EF.CBMID 6F48`, `menu title: EF.SUME 6F54`, the URI set, `SUCI data`)
+  are informational — the service does not declare a file of its own.  The
+  §A.4 RFU/reserved rows are not features and therefore have no entry.
+
+The **Check filesystem** button (Services pill, needs a card) reads the four
+service tables, probes the file manager's tree once (`pysimFsProbeAll`; the
+`/api/tree` model lists files without testing them, so a loaded-but-unprobed
+tree proves nothing), and compares the two sides:
+
+- `missing` — a **declared** feature (any of its service bits set in a present
+  file; EF.SST only at *allocated + activated*, the state the editor shows)
+  whose mapped FIDs are absent from the card.  In §A order.
+- `extra` — a **present** FID that no declared feature maps.  Sorted by FID,
+  naming every feature that maps it (all of them undeclared).  A FID **any**
+  declared feature maps counts as explained and is not reported: several
+  features share one file (`4F01` under the ACDC/MCS/5GS/V2X/5G ProSe/5MBS/A2X
+  DFs, `6F4A`/`6F4B` across EXT1/EXT2 and BDN) and the rule cannot tell which
+  DF the present copy sits in.
+
+The check is **FID-level, not (DF, FID)-exact** (this first pass; finding 6 in
+`docs/decoded-editing.md` asks for DF-scoped resolution).  The FID collisions
+of Notes §3 — `6F4E` EXT4/EXT5, `6F4F` ECCP/CCP2, `6F07` IMSI/IST, `6F38`
+SST/UST, `6FD7` MSK/GBANL, `5F3B` DF.GSM-ACCESS/DF.MULTIMEDIA — are therefore
+not disambiguated, and the report says so.  `EF.PBR 4F30` also exists in
+several DFs, so a present `4F30` explains `ADN`/`SoLSA` regardless of which
+copy it is.
+
+The pure pieces (`servicesFsDeclared`, `servicesFsPresentFids`,
+`servicesFsReport`, `servicesFsReportHtml`) are DOM-free and unit-tested; the
+last report is kept in memory and redrawn on a language switch, and it is
+dropped with the cached reads on a card-session change.
+
 ### B.1 `capability` entries (no single file)
 
 CHV1 disable · Data download via SMS-PP · Data download via SMS-CB (gate
@@ -251,7 +295,7 @@ The three initially-unresolved mappings were settled from the spec text
 - **eCall Data (89)** — no dedicated EF: the eCall test/reconfiguration
   numbers live in **EF.SDN 6F49** ("If service n° 4 and/or n° 89 is available
   this file shall be present … eCall test and reconfiguration numbers") and
-  EF.FDN 6F3A (the eCall procedures).
+  EF.FDN 6F3B (the eCall procedures).
 - **eCall Data over IMS (112)** — the eCall test/reconfiguration **URIs** live
   in **EF.SDNURI 6FEF** (and EF.FDNURI 6FED).
 - **EARFCN list for MTC/NB-IOT UEs (121)** — **EF.EARFCNList 6FFD** (§4.2.112,