Phase 10a v1.2.0: MIT license, metadata update, full API docs

- Bump idf_component.yml to v1.2.0 with MIT license, targets, tags
- Add LICENSE (MIT) for IDF Component Registry compatibility
- Update CHANGELOG.md with v1.2.0 entries (portal, stratum_client, mint_health, client)
- Update README.md with all 13 modules documented, API reference table
- Add REMAINING_PLAN.md with full execution plan and checklist
- 25 unit tests pass, ESP-IDF build passes

1 files changed, 63 insertions, 11 deletions

diff --git a/components/tollgate_core/README.md b/components/tollgate_core/README.md
index d83d634..57bab4d 100644
--- a/components/tollgate_core/README.md
+++ b/components/tollgate_core/README.md
@@ -4,14 +4,27 @@ ESP-IDF component providing paid WiFi hotspot logic with Cashu e-cash payments.
 
 ## Features
 
-- **Session management** — time-based and bytes-based sessions with auto-expiry
-- **Cashu token processing** — decode Cashu e-cash tokens, calculate allotments, multi-mint support
-- **Per-client firewall** — whitelist-based NAT filtering with sandbox mode
-- **DNS server** — per-client DNS hijack/forward with DoT rejection
-- **Mining payment** — Stratum share tracking, hashprice calculation, difficulty conversion
-- **Stratum proxy** — transparent TCP proxy for mining traffic with job management
-- **Beacon price** — WiFi vendor IE construction for price/mint/geohash advertising
-- **Market scanner** — discover and compare nearby TollGate prices
+### Session & Payment
+- **Session management** (`tollgate_core_session`) — time-based and bytes-based sessions with auto-expiry, extension, and revocation
+- **Cashu token processing** (`tollgate_core_cashu`) — decode Cashu e-cash tokens, calculate allotments, multi-mint support, proof state checking
+- **Per-client firewall** (`tollgate_core_firewall`) — whitelist-based NAT filtering with sandbox mode for unauthenticated clients
+
+### Network
+- **DNS server** (`tollgate_core_dns`) — per-client DNS hijack/forward with DoT rejection
+- **Stratum proxy** (`tollgate_core_stratum_proxy`) — transparent TCP proxy for mining traffic with job management
+
+### Mining
+- **Mining payment** (`tollgate_core_mining`) — Stratum share tracking, hashprice calculation, difficulty conversion, share-to-allotment mapping
+- **Stratum client** (`tollgate_core_stratum_client`) — Stratum V1 JSON protocol parsing (mining.notify, mining.set_difficulty), message construction (subscribe, authorize, submit)
+
+### Discovery & Market
+- **Beacon price** (`tollgate_core_beacon`) — WiFi vendor IE construction for price/mint/geohash advertising
+- **Market scanner** (`tollgate_core_market`) — discover and compare nearby TollGate prices via vendor IEs
+- **Mint health** (`tollgate_core_mint_health`) — mint health state tracking with recovery threshold, reachable/unreachable transitions
+
+### Portal & Client
+- **Portal rendering** (`tollgate_core_portal`) — HTML template rendering with multi-key substitution, usage calculation, captive URI detection
+- **TollGate client** (`tollgate_core_client`) — upstream TollGate discovery JSON parsing, session/usage response parsing, renewal threshold logic, price comparison
 
 ## Integration
 
@@ -26,7 +39,15 @@ static tollgate_platform_t platform = {
     .get_mint_url = my_get_mint_url,
     .get_metric = my_get_metric,
     .get_time_ms = my_get_time_ms,
-    // ... other callbacks
+    .spend_proofs = my_spend_proofs,
+    .get_stratum_url = my_get_stratum_url,
+    .get_stratum_port = my_get_stratum_port,
+    .get_stratum_user = my_get_stratum_user,
+    .get_stratum_pass = my_get_stratum_pass,
+    .get_mining_port = my_get_mining_port,
+    .get_hashprice_sats_per_ghs_day = my_get_hashprice,
+    .on_share_accepted = my_on_share_accepted,
+    .get_hashrate = my_get_hashrate,
 };
 ```
 
@@ -54,9 +75,40 @@ tollgate_core_process_payment(client_ip, cashu_token_string);
 
 Call `tollgate_core_tick()` periodically (e.g., every second) to expire sessions.
 
+### 5. Use sub-modules directly
+
+```c
+#include "tollgate_core_portal.h"
+char *html = tollgate_core_portal_render(template, subs, nsubs);
+
+#include "tollgate_core_stratum_client.h"
+tollgate_core_stratum_build_subscribe(buf, size, req_id);
+
+#include "tollgate_core_mint_health.h"
+tollgate_core_mint_health_update(&state, idx, probe_ok, status, err, time);
+
+#include "tollgate_core_client.h"
+bool renew = tollgate_core_client_should_renew(remaining, allotment, threshold);
+```
+
 ## API Reference
 
-See `include/tollgate_core.h` for the public API and `include/tollgate_platform.h` for platform callbacks.
+| Header | Description |
+|--------|-------------|
+| `tollgate_core.h` | Main API: init, process_payment, tick, status queries |
+| `tollgate_platform.h` | Platform callback struct definition |
+| `tollgate_core_session.h` | Session create/find/extend/revoke |
+| `tollgate_core_cashu.h` | Token decode, checkstate, allotment |
+| `tollgate_core_firewall.h` | Client grant/revoke, sandbox ports |
+| `tollgate_core_dns.h` | DNS start/stop |
+| `tollgate_core_mining.h` | Share tracking, hashprice, difficulty |
+| `tollgate_core_stratum_proxy.h` | Proxy init/stop, job management |
+| `tollgate_core_beacon.h` | IE construction, mint/npub hashing |
+| `tollgate_core_market.h` | Market table, price comparison |
+| `tollgate_core_portal.h` | Template rendering, usage calc, captive URIs |
+| `tollgate_core_stratum_client.h` | Stratum V1 protocol parsing |
+| `tollgate_core_mint_health.h` | Mint health state tracking |
+| `tollgate_core_client.h` | Discovery/session parsing, renewal logic |
 
 ## Dependencies
 
@@ -68,4 +120,4 @@ See `include/tollgate_core.h` for the public API and `include/tollgate_platform.
 
 ## License
 
-Proprietary — see repository for details.
+MIT — see [LICENSE](LICENSE).