Multi-day accumulated fixes: tag dispatch, session/pooling correctness, SPA rollout, jetc compiler

JetCore engine (Tag.cpp/.h, Global.cpp/.h, __*.cpp tag classes):
- Numerous __mysql.cpp connection-pooling correctness fixes (stale
  result sets, double-indirection sessionid bugs, field caching,
  pool keying) and a session-registration-before-connection-confirmed
  ordering fix (dangling pointer on a failed connect)
- Tag.cpp: large body of fixes to the tag-dispatch/container-scanning
  logic (bare-name fallback, database aliasing, single-quote handling,
  @-prefix session variable resolution, TAGDEF caching, nested split-tag
  scanning for if/while/until/ifrow so an inner one doesn't corrupt an
  outer one's own boundary scan) plus the process-first rendering
  order fix (a <process> now runs before <checksession>/page
  resolution, fixing a real "blank page after successful login" bug)
- Global.h/.cpp: added imapSessions (parallel to the existing __mysql*
  session map) for the new <imap> tag family
- __whiledir.cpp/__include.cpp: caching and directory-name-aliasing
  fixes
- __call.cpp/.h: fixed a dangling-pointer bug
- __write.cpp: fixed an O_WRONLY-only open that couldn't create a new
  file
- __ifrow.cpp/__sql.cpp: fixed the same sessionid double-indirection
  bug __mysql.cpp had (resolveKeyword's result was being used as a map
  key lookup instead of the resolved value itself)

jetc compiler (jetc/JetParser.cpp/.h, JetCodegen.cpp/.h, JetAST.h,
jetc.cpp, build-shared.sh, build-compiled.sh):
- Parser fixes: inline <include>, nested-quote handling, void-tag
  recognition
- Codegen fixes and expanded AST support
- build-shared.sh: atomic rename into place for a freshly-built .jtc
  (a live server dlopen()ing the same path mid-rebuild was corrupting
  its own already-mapped view of the old file) and a staleness check
  so a cached JetCore .o doesn't silently keep serving yesterday's
  fixes forever
- Added -lssl to both build scripts' link lines (needed once the new
  <imap> tag's client-side TLS code existed - previously nothing in
  this codebase used OpenSSL's SSL/TLS client API, only libcrypto)

Site content (jetc/barant-site/): SPA (fetch-and-swap navigation)
rollout across essentially every .page/.jet/.section/.tag/.proc/.method
file - dynamic-content fixes, fragment-mode stripping, native
$[@name] session variables replacing older mechanisms, and this
session's own checkout.page redesign, login start-param redirect fix,
and per-page side-menu (menu.bar/$[PAGE].menu) refresh support.
Completed the earlier main.css/control.css move from assets/ to
assets/images/ (git still showed the old paths as tracked-but-deleted
until now).

Deliberately left out of this commit: dozens of .pre-<description>-
<date> manual backup files (this session's and earlier ones' own
before/after snapshots, not meant for permanent history), compiled
.jtc build outputs, ad hoc test binaries and scripts under jetc/
(login_asan, wcwc_test, optest2_bin, etc.), and jetc/__pycache__/ -
none of these are meant to be tracked; a .gitignore covering them
would be worth adding separately.

Global.h

@@ -11,7 +11,9 @@
 namespace  jet {
 
    class __mysql;
-   
+   class __imap;
+   class Tag;
+
    class Global {
 
     public:
@@ -23,6 +25,10 @@ namespace  jet {
       void addSession(coreutils::MString sessionId, __mysql *mysql);
       void removeSession(coreutils::MString sessionId);
       __mysql * getSession(coreutils::MString sessionId);
+      bool imapSessionExists(coreutils::MString sessionId);
+      void addImapSession(coreutils::MString sessionId, __imap *imap);
+      void removeImapSession(coreutils::MString sessionId);
+      __imap * getImapSession(coreutils::MString sessionId);
       coreutils::ZString getSessionVariable(coreutils::MString &splitName);
       void outputHeaders();
       void setupFormData(coreutils::ZString &formdata);
@@ -55,10 +61,32 @@ namespace  jet {
       std::map<coreutils::MString, __mysql *> sessions;
       std::map<coreutils::MString, coreutils::MString> headers;
       std::map<coreutils::MString, coreutils::MString> tags;
+
+      // Populated once per compiled .jtc module's own entry function (see
+      // jetc's TAGDEF codegen) - a top-level <tag name="X"> definition
+      // that jetc could compile directly registers its own render
+      // function here under its lowercase name, same key convention as
+      // `tags` above. __dotag checks this first before falling back to
+      // the text-based findTagDefinition()/processContainer() path (see
+      // __dotag.cpp), avoiding a full re-parse of the definition's body
+      // on every invocation. A miss here (a locally-scoped/nested tag
+      // definition, or content that was never compiled at all) is always
+      // safe - it just means the existing interpreted path runs exactly
+      // as it always has; this is a pure additive fast path, never a
+      // replacement for `tags`, which every TAGDEF still populates too.
+      std::map<coreutils::MString, void(*)(Tag&, coreutils::MString&)> compiledTags;
+
       char **envp;
       bool cgi = false;
       bool session = false;
       coreutils::MString sessionId;
+
+      // Deliberately the LAST member declared in Global - appended
+      // here, after every pre-existing field, rather than inserted
+      // earlier among them, so this addition does not shift the
+      // memory offset of any field that existed before it. See
+      // __imap.h for what registers here.
+      std::map<coreutils::MString, __imap *> imapSessions;
       
    };