Install patches via sceAppInstUtilAppInstallPkg; fix GetInstallStatus ABI

sceAppInstUtilInstallByPackage returns 0x80B21163 from payload context
(process privilege rejection). sceAppInstUtilAppInstallPkg accepts the
same PKG with rc=0 and does install it. Switch all install paths to use
AppInstallPkg.

do_install (cross-region): require assembled PKG from the manifest
download; InstallByPackage and DP.pkg fallbacks are removed since both
are dead ends in this process context. do_install (same-region): also
switched to AppInstallPkg. do_download: removed the DP.pkg shortcut so
the manifest-assembled full PKG is downloaded as before.

sceAppInstUtilGetInstallStatus ABI: first arg is an output buffer for
the current install's content_id, not an input query. Passing our
tracking buffer there was overwriting it with zeros (disc game has no
explicit content_id). Fix: use a fresh output buffer; keep `cid` from
g_last_content_id untouched. Also add 2048-byte padding to
ai_install_status_t against firmware struct size variance.

New APIs: patchdl_install_by_uri, patchdl_install_app_pkg,
patchdl_install_debug_state. New endpoints: /api/install_uri,
/api/install_aip, /api/debug_install. delta_url propagated through
verxml → scan → websrv for future DP.pkg tracking.

Verified on device (FW 11.60, BD-JB+PPPwn): Dead Island 2 PPSA03099
updated from 01.000.001 to 01.000.011.

src/patchdl_install.h

@@ -42,3 +42,25 @@ int patchdl_install_pkg_meta(const char *local_path, char *content_id, size_t ci
 /* Read-only: report the last AppInstUtil install task PatchDL started, using
    sceAppInstUtilGetInstallStatus when present. No install, no mutation. */
 int patchdl_install_status_json(char *out, size_t out_sz);
+
+/* Raw dump of g_last_* tracking state (no AppInstUtil call). For diagnosis. */
+void patchdl_install_debug_state(char *out, size_t out_sz);
+
+/* Install a package from a remote URI (http:// or file://) directly, without
+ * requiring a local copy. Used for shared-master delta packages where the
+ * version.xml targets a different title id than the CDN storage path.
+ * `target_content_id` is the installed title's content_id (passed as
+ * MetaInfo.content_id so AppInstUtil binds the install to the right title).
+ */
+int patchdl_install_by_uri(const char *uri,
+                            const char *target_title_id,
+                            const char *target_content_id,
+                            char *msg, size_t msg_sz);
+
+/* Directly call sceAppInstUtilAppInstallPkg for a local file. No MetaInfo —
+ * AppInstUtil reads the PKG's embedded content_id/title_id for routing.
+ * Use when InstallByPackage is unavailable (privilege). */
+int patchdl_install_app_pkg(const char *local_path,
+                             const char *expected_title_id,
+                             const char *target_content_id,
+                             char *msg, size_t msg_sz);